At 047 hours on the morning of July 30th, 1943, Wing Commander Roland Musen watched the pale green return on his radar screen drift from the right edge toward the center and held his Wellington level at 800 ft above the Bay of Bisque.

The sea below was black and indistinguishable from the sky.

No moon, no horizon, nothing visible beyond the instrument glow of the cockpit and the quiet breathing of his crew over the interphone.

But the radar did not care about darkness.

The radar was showing him a shape on the surface of the water, 1.4 mi ahead that had not been there 20 minutes ago.

A shape moving northwest at 6 knots, diesel electric, surfaced, charging batteries.

The Yuboat’s commander believed the night protected him.

He had no reason to think otherwise.

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No Allied aircraft had ever found him in darkness like this.

His radar warning receiver was silent.

He had surfaced to breathe and to charge his batteries for the submerged run toward the Atlantic convoy routes, and the Bay of Bisque at 0147 hours in the summer of 1943 was as safe as it had ever been for a German submarine commander.

He was wrong.

Musan reached down and flipped the arming switch on the Lee light.

21 minutes later, U614 was on the bottom of the Bay of Bisque with all 50 hands.

Capitan Litant Wolf Gang Strata and his crew had seen nothing until 22 million candle power of search light erupted from the underside of an aircraft they had not known was there, illuminating every detail of their conning tower and pressure hull at a range of 800 yd.

And by then the Wellington was already in its attack run, and the depth charges were already falling, and there was no time left for anything except to understand that the darkness they had trusted had become the weapon that killed them.

Roland Mason landed at RAF Chivvenor in Devon at 0600 hours on July 30th, filed his contact report, and drank his tea.

He had been hunting submarines in the Bay of Bisque for over a year.

He commanded the squadron that had invented this kind of warfare.

The squadron that had first proven that the knight belonged not to the submarines, but to the aircraft that had learned to find them in it.

He had 25 days left to live.

It was not a battle.

It was the end of something Yuboat commanders had believed was permanent.

The darkness that had killed 3 million tons of Allied shipping in 1942 was gone.

It had been taken by a search light attached to a Wellington bomber, by a radar that could see shapes on the surface at 2 mi in absolute darkness by the men of one squadron based in North Devon, who had spent 18 months turning a technological idea into operational reality.

When MSON’s depth charges destroyed U614 on July 30th, it was the sixth Yubot the squadron had sunk since March.

In July alone, coastal command aircraft killed 12 German submarines in the Bay of Bisque.

Admiral Carl Dunitz, the commander of the Yubot fleet, had already begun to understand that something fundamental had changed.

The submarines that crossed the bay at night were dying at a rate his fleet could not sustain.

The passage that had once been the safest part of every patrol had become a killing ground.

This is the story of how a single technological idea removed the most powerful tactical advantage in the Battle of the Atlantic.

How a retired naval officer spent 2 years convincing a skeptical air ministry to mount a powerful search light under the wing of a bomber.

And how that search light ended the Yubot’s dominion over the surface of the ocean at night.

How the men of 172 Squadron at RAF Shivvenor flew patrols over empty ocean for hundreds of hours to kill submarines one at a time.

Each kill representing a crew of 50 men and an aircraft that had taken months to build and could not be replaced.

How Roland Musen commanded that squadron to its most destructive summer and died 25 days after his greatest single success in circumstances so ordinary that they still resist understanding.

and how the hubot that survived the summer of 1943 never again crossed the Bay of Bisque with confidence in what the darkness could keep secret.

I spent 10 hours writing, editing, and researching this story, paying attention to every detail to honor the men of 172 Squadron and the crews of the submarines they hunted.

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Humphrey Diver Lee had retired from the Royal Naval Air Service after the First World War and gone into business.

He was 50 years old in 1940, a former squadron commander with a desk in the Air Ministry when he first proposed the idea that would change the battle of the Atlantic.

The problem he was trying to solve was precise and brutal.

German Ubot had to surface at night to recharge their batteries.

A surfaced Ubot in darkness was virtually impossible to attack.

Aircraft with radar could find them on the surface, could track them on the radar screen as they closed from miles away, could follow their course and calculate their speed and position, and then at approximately 1 mile when the pilot descended to attack altitude, and switched the radar to its shorter attack range.

The radar return disappeared into sea clutter.

The submarine was there somewhere ahead in the darkness, invisible from 800 ft and closing at the aircraft’s approach speed.

and the pilot had perhaps 10 seconds to find it visually before he overflew it.

Usually he did not find it.

Usually the depth charges fell in empty water and the yubot dived unharmed and surfaced again an hour later.

Lee’s solution was simple and had been obvious to anyone who thought carefully about the problem for more than a few minutes, which is perhaps why the air ministry took so long to implement it.

The radar acquired the target at long range.

The aircraft followed the radar track until it was close enough for a search light to illuminate the target at short range.

The pilot used the search light to aim his attack.

The gap between radar detection and visual acquisition, the gap in which submarines had been escaping for years was closed by light.

22 million candle power of light installed in a retractable housing under the Wellington’s fuselage powered by a dedicated generator controlled by the aircraft captain deployable in the final seconds of an attack run.

The Air Ministry did not immediately approve the lay light.

This is worth understanding because the delay cost ships and lives between 1940 and 1942.

While Lee’s proposal worked its way through committees and assessments and competing proposals and bureaucratic resistance, German submarines were destroying Allied shipping at rates that threatened Britain’s ability to continue the war.

In 1942 alone, Yubot sank over 6 million tons of Allied shipping.

7 million tons had entered British ports in 1930s normal trade.

The arithmetic of survival for an island nation dependent on imported food and fuel and raw materials was becoming frightening.

Yubot were winning the battle of the Atlantic and the primary reason they were winning at night was the gap that Lee’s search light would have closed.

The Helmore Light was the competing proposal, a more powerful system mounted in the nose of a bow fighter.

Air Ministry preference had favored the Helmore design in 1941.

After months of trials, the Helmore Light was found to be impractical in operational conditions.

Lee’s simpler and more reliable design was finally authorized.

By February of 1942, number 1417 Lee Lightflight had been formed at RAF Chivvenor in Devon.

By April, it had become number 172 Squadron, the first Lee Light Squadron in coastal command.

The first operational patrol flew on the night of June 3rd, 1942.

The crew of Wellington F for Freddy, captained by squadron leader Jefferson Greswell, was 40 minutes into a routine patrol across the southern bay of Bisque when the radar operator called a contact.

The return was faint but consistent, moving northwest at standard submarine surface speed.

Greswell tracked it for 12 minutes on the radar, descending as he closed, keeping the radar on long range until the last possible moment.

And then at 800 yd, he activated the Lee Light for the first time in combat.

The Italian submarine Luigi Tellerelli was caught on the surface charging batteries, her crew completely unaware that an aircraft had been following them in darkness for 12 m.

The Terelli’s captain had time to see the light before Greswell’s depth charges hit the water beside him.

He reached the Spanish coast and beed his submarine to prevent sinking.

The light had worked exactly as Lee had designed it to work.

The principle was proven on the first night it was tested in combat.

Number 172.

Squadron’s first confirmed kill came exactly one month later on July 5th, 1942 when pilot officer Wy Howell of the United States Army Air Force, one of the Americans who had joined the RAF before his own country entered the war, sank U502 in the Bay of Bisque using the Lee light combination.

U502 was conducting her sixth war patrol.

She had previously sunk eight Allied ships totaling over 43,000 tons.

She sank in minutes after Howell’s depth charges.

No survivors.

Howell returned to Chivvenor, filed his report, and his wing commander recommended him for a decoration.

It was the first yubot sunk by coastal command using the radar and search light combination that Lee had spent two years persuading the air ministry to build.

Roland Gascoin Musen had taken command of a 172 squadron in early 1943.

He was a wing commander, a former celebrity pilot who had competed in air races before the war.

A man whose instinct for aircraft performance had been developed in competition rather than combat, but whose physical courage and methodical precision had made him effective as a squadron commander.

In a campaign where the most dangerous variable was not the enemy, but the aircraft itself, Wellington bombers hunting submarines at low level over open ocean in darkness and bad weather were at constant risk from the same conditions that made their work effective.

The Bay of Bisque in winter produced seas that could flip aircraft attempting low attacks in rough air.

In summer, fog and cloud could close airfields while aircraft were still overwater.

Night navigational errors could put aircraft into high ground that lookouts could not see in time.

Musan understood these risks with the precision of a pilot who had spent years flying in competition where errors of judgment produced immediate and unforgiving consequences.

He had flown enough bay patrols to know that the operational losses of 172 squadron came as often from weather and navigation as from yubot anti-aircraft fire.

that the enemy that killed his crews most reliably was not the German submarine commander, but the combination of darkness, confusion, and terrain.

He flew the missions himself rather than directing from the ground because he believed a squadron commander who did not share the risks he imposed on his crews was asking something he should not ask.

He was wrong about only one thing, and it killed him.

But that comes later.

The summer of 1943 was the turning point of the Battle of the Atlantic, though the men living through it could see this only imperfectly.

In May, the German submarine fleet had lost 41 boats in a single month.

It was the most catastrophic monthly loss in the history of submarine warfare.

Jonitz had briefly withdrawn his submarines from the North Atlantic convoy routes, not abandoning the campaign, but recognizing that the tactics and equipment he had been using since 1939 had been overtaken by Allied counter measures, improved radar in escort vessels, more longrange aircraft closing the Mid-Atlantic gap, escort carriers accompanying convoys.

The combination of improvements that had accumulated through 3 years of desperate Allied adaptation had suddenly become overwhelming.

But the Bay of Bisque campaign was separate from the convoy battle and connected to it.

Every yubot that sailed from Laurant or Breast or La Palis to attack Atlantic convoys had to cross the bay.

The bay was 250 mi wide at its narrowest point, deep enough that submarines could not hug the coast.

They had to cross open water.

And since the night of June 3rd, 1942, when Greswell had illuminated the Luigi Terelli and proved that darkness was no longer protection, 172 Squadron and its successors had been systematically hunting those crossings.

The hubot could stay submerged during daylight, but they had to surface at night to charge batteries, and when they surfaced, the Wellington crews at Chivvenor were waiting with radar that could see them from 2 mi and a light that could illuminate them from 800 yd.

What the Yubot commanders experienced during this period is worth understanding from their side, because the tactical situation they faced was precisely the mirror of what the crews at Chivvenor were attempting to create.

A hubot in the Bay of Bisque in mid 1943 was a vessel conducting a crossing of 250 mi of ocean that its commanders had once considered routine.

They surface at night, run the diesel engines to charge the batteries, breathe fresh air, allow the crew onto the bridge in watches, and cover as many miles as possible before the approaching dawn force them back under.

The crossing could take four or 5 days, depending on weather and the state of the batteries.

The crew needed those knights on the surface.

Without them, the batteries ran down to the point where the boat became difficult to maneuver submerged, and the air below became foul enough to degrade the crew’s ability to function.

The MTOX receiver had restored confidence in this routine after its introduction.

The audible signal that told a commander an aircraft’s radar emissions had been detected gave crews time to dive before the aircraft could close to attack range.

The receiver gave specific warning.

It gave time.

And in late 1942, it worked reliably enough that yubot crossing losses dropped significantly and commanders resumed surface operations at night with relative confidence.

They had a weapon against the aircraft.

The weapon worked.

The routine was safe again.

The centimetric radar removed this confidence without warning.

The first Yubot crews who went down to attacks from aircraft.

Their Mtox receivers had not detected in early 1943 could not have known why.

They surfaced.

The Mtox was silent and then a search light erupted from 800 yd and depth charges hit the water beside them.

The boats that were damaged but survived might have reported the failure of the Mtox to give warning, but their reports could not answer the question of why.

The wavelength shift that had made the Mark III invisible to the Mtox was not something Yubot crews could diagnose from operational experience.

They knew only that the night had stopped being safe in a way they could not explain, that their warning device was not warning them, that the bay was killing boats that had done everything correct.

The psychological impact of this uncertainty was as damaging as the physical losses.

A crew that cannot trust its warning equipment cannot sleep soundly when it must surface to survive.

The Germans had developed countermeasures.

The MTOX radar warning receiver, introduced in mid 1942, could detect the emissions of British ASV Mark II radar and alert Yubot commanders that an aircraft was nearby, giving them time to dive before it closed to attack.

For several months in late 1942, the MTOS had effectively defeated the Lee light patrols.

Submarines dove before aircraft got close enough to use the search light.

Coastal Command’s kill rate fell to nearly zero.

The Knights belonged to the submarines again.

The answer was centimetric radar.

The ASV Mark III operated on a wavelength of 10 cm rather than the 1.5 m of the MK2.

The MOX receiver was tuned to detect the MK2’s frequencies.

It was deaf to the Mark III.

When coastal command introduced sentimentric radar in early 1943, the MTOX devices on German submarines stopped working as warning systems without the submarine commanders knowing they had stopped.

Hubot surfaced with confidence in their MTOX receivers and found Lee lights erupting from aircraft they had not detected.

The combination of Mark III radar and the Lee Light was the decisive technological pairing that made July 1943 so catastrophic for the Yubot fleet.

Musan flew the patrol on the night of July 29th to 30th in Wellington J for Juliet, departing Chivanor at 2200 hours and descending to patrol altitude over the bay approximately 40 minutes later.

The patrol route was standard, covering the transit corridor used by submarines moving between the Bisque bases and the Atlantic.

Most patrols were unrewarding.

A crew might fly 8 or 9 hours over empty ocean and return without a contact.

This was not failure.

The purpose of constant patrolling was to force submarines to stay submerged and slow and unable to charge batteries to make the crossing so dangerous that the cost of maintaining the Atlantic campaign would eventually exceed what the German Naval Command was willing to pay.

Individual kills were the dramatic proof of the campaign’s effectiveness, but the hours of empty patrol contributed equally to the result.

Every submarine that chose to stay submerged because it feared air attack was a submarine that was not attacking convoys.

The radar contact at 0134 hours showed a target bearing 240° at a range of 1.6 mi.

Musen noted the contact’s course and speed in the log, adjusted his heading to intercept, and descended from 1500 ft to 800 ft as he closed.

The Mark III radar held the contact clearly throughout the approach.

the return strengthening as the range decreased.

At 800 yards, Musen activated the Lee light.

What Wolf Gang Straighter saw from the bridge of U614 in that moment has no surviving account.

Straighter went down with his boat and all 50 of his crew.

The Wellington’s depth charges bracketed the submarine in the standard pattern set to detonate between 20 and 30 ft.

The pressure of the detonations designed to rupture the pressure hull or damage propulsion and control systems.

Muen’s attack report submitted after landing described the attack as accurate and the result as a certain sinking.

Postwar cross referencing of German records with British contact reports confirmed the destruction of U614 on that date and in that position.

Strata had left Laurant on July 21st on what was U614’s second war patrol.

She had no previous kills.

She would not get them.

Muen returned to Chivvenor, slept, ate, and continued the work of commanding a squadron in the most productive period of its operational existence.

In July 1943, a 172 squadron was contributing to a campaign that was destroying the German submarine fleet at a rate it could not replace.

Not individual boats, not individual captains.

the cumulative irreplaceable experience of crews who had survived enough patrols to understand their work, who had learned which tactics worked and which did not, who had brought that knowledge back from operations that killed most of the men who attempted them.

A yubot crew that sank was not just 50 men in one submarine.

It was 50 men’s worth of accumulated operational knowledge about convoy approach tactics, about how to evade escort destroyers, about the physics of deep diving in damaged boats.

That knowledge ended at the bottom of the Bay of Bisque and could not be reconstructed in training schools in Germany.

On the afternoon of August 24th, 1943, the entire compliment of 172 squadron assembled on the tarmac in front of a Wellington for a squadron photograph.

Wing Commander Roland Muen sat in the center of the first row, flanked by his senior officers.

The photograph survives in archives.

Musen is dressed in standard RAF uniform, seated with the calm of a man who has been in command long enough that it feels normal, surrounded by the men he had led through the most successful period of the squadron’s history.

The crews who had sunk yubot, the ground crews who had maintained the Lee lights and the radar sets through North Devon winters, and the constant stress of operational flying, the mechanics and armorers and signals officers who made the patrols possible.

They stood in front of their aircraft on a summer afternoon in Devon and they did not know what the night was going to do.

Musen took off from Chanor that night on a standard bay patrol.

The Wellington climbed over the North Devon coast, crossed Bideford Bay, and turned southwest toward the patrol area.

What happened next was the subject of a court of inquiry that concluded nothing definite.

The court could not determine whether it was pilot error or a navigational instrument error.

What is known is that the aircraft made an unusual turn above Cloverly, the fishing village on the North Devon coast, when standard procedure required the turn to be made further out over the sea above H Heartland Point.

Flying at 700 ft, Musen’s Wellington turned inland above a headland where the ground rises steeply from the water.

The aircraft struck overhead power lines near Higher Cloverly before hitting the ground and exploding.

Musen was killed along with every member of his crew.

The heading of the aircraft at the moment of impact suggested that the crew believed they were over H Heartland Point and the sea when they were in fact over Cloverly and rising ground.

A navigation error of perhaps 2 mi.

At 700 ft over the sea, 2 mi was irrelevant.

At 700 ft over the North Devon coast, 2 mi was the difference between the water and the cliffs.

25 days after sinking U614 6 days before his crew photograph would have been developed and distributed.

Wing commander Roland Musen is buried at Heington Punchedan Church above Chivvenor together with flight left tenant Leslie Herbert Burden, one of his crew.

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The squadron continued without him.

His successor inherited a unit that had sunk six yubot in 5 months that had contributed to making the Bay of Bisque as lethal to German submarines as the bay crossing was supposed to be lethal to Allied shipping.

By the autumn of 1943, Dernit’s response to the bay losses had become visible in change tactics.

Submarines began crossing the bay on the surface during daylight rather than at night, accepting the risk of visual sighting by aircraft because at least in daylight they could see the aircraft approaching and man their anti-aircraft guns and fight back.

This was counterintuitive, but the arithmetic supported it.

The Lee Light had made night surface transit more dangerous than daylight surface transit.

The submarine commanders who had once trusted darkness were now trusting their anti-aircraft gunners instead.

This shift produced new casualties on both sides.

Submarines fighting on the surface in daylight could inflict serious damage on lowaltitude attacking aircraft before being sunk.

Flying officer William Jennings of 172 Squadron was lost on July 24th when anti-aircraft fire from a surfaced hubot hit his Wellington and killed or incapacitated both pilots on his final attack run.

The Wellington flew straight into the submarine.

The depth charges detonated on contact and both aircraft and hubot were destroyed together.

These were the equations of a campaign where every tactical change produced a counterchange where survival depended on anticipating how the enemy would respond to the last innovation and preparing the next one before he did.

The tactical response to daylight surface transit was coordinated attacks by multiple aircraft.

The same principle that escort carriers and destroyer groups were applying to convoy defense.

One aircraft attacking a submarine on the surface encountered concentrated anti-aircraft fire.

Two aircraft attacking from different angles split the fire.

Three aircraft made the defensive fire ineffective.

Coastal command began organizing group patrols where multiple aircraft swept the same areas and could concentrate on a contact together.

The submarines that adopted daylight group transit in turn found themselves facing multiple aircraft simultaneously.

The tactical escalation continued through the rest of 1943 as each side adapted to what the other had most recently learned to do.

But the fundamental equation of the Bay campaign had been settled in the summer of 1943 by the combination that Lee had first proposed in 1940 and Musen had commanded to its operational peak.

The Ubot could no longer treat the bay crossing as routine.

They could no longer surface in darkness and assume safety.

Every hour on the surface was a risk that had to be calculated against the need to charge batteries and breathe and allow the crew to stand on the open bridge after days submerged in a pressure hull.

The psychological weight of that calculation, the constant awareness that a radar equipped aircraft might be approaching from any bearing at any moment degraded the operational effectiveness of yubot crews in ways that were difficult to measure but real in their consequences.

Men who could not sleep soundly because they were always listening for the sound of aircraft engines made mistakes.

Commanders who surfaced for 4 hours instead of eight because they feared the night left their batteries partly charged and their options reduced.

Admiral Dunit wrote in his war diary in the autumn of 1943 that the Bay of Bisque had become a valley of death for his submarines.

The phrase was precise.

69 yubot were ultimately lost in the bay during the entire course of the war.

A significant fraction of total yubot losses concentrated in a transit area that submarines had once crossed with confidence.

The Valley of Death had been created largely by the men of 172 Squadron and the squadrons that followed their methods, by the Lee Light that Humphrey Lee had spent 2 years persuading the Air Ministry to build, and by the sentiment radar that had finally removed the Mtox receivers’s ability to give submarines warning of approaching aircraft.

Humphrey Lee was awarded the Order of the British Empire for his invention.

He received it at Buckingham Palace in late 1943 and died in 1959 at the age of 69.

The citation for his award described the operational impact of the Leight in terms that the official language of military decorations rarely achieves.

The light that bore his name had contributed to turning the tide of the Battle of the Atlantic at a moment when the arithmetic of that battle was still uncertain.

The ships that reached Britain in the second half of 1943, carrying food and fuel and weapons and men crossed an Atlantic made progressively safer by a search light and a radar and the crews of the Wellington bombers who had learned to use them together.

The Vicar’s Wellington itself deserves mention in this account because the aircraft that made the Lee light patrols possible was a machine that should not have worked as well as it did.

Barnes Wallace, who would later design the bouncing bombs used against the Ruer Dams, had designed the Wellington’s geodessic airframe in the 1930s.

The geodessic structure was a latis of lightweight metal struts, each one contributing to the strength of the hole.

The load distributed across the entire structure rather than concentrated in specific spars and frames.

This made the Wellington extraordinarily resistant to structural damage.

Anti-aircraft fire that would have severed a conventional spar, causing a wing to fold or a fuselage to break, instead punched holes through a geodeic frame that continued to function.

Crews brought Wellington’s home from patrols with sections of fuselage torn open with hydraulic systems destroyed with control surfaces partly shot away because the underlying structure that kept the aircraft flying remained intact when similar damage would have destroyed a conventionally built aircraft.

This mattered for the Lee light patrols because the final approach to a surface submarine was the most dangerous moment of the mission.

At 800 yards and closing at low altitude with the Lee light on, the Wellington presented a large and clearly illuminated target to any hubot crew with anti-aircraft guns and the reaction time to use them.

Some didn’t have time, others did.

The aircraft that survived anti-aircraft fire during attack runs survived partly because their geodessic construction allowed them to absorb damage that would have been fatal to other types.

The aircraft that flew Masan’s crew to their deaths on the night of August 24th was not shot down.

It was not destroyed by yubot gunfire.

It was destroyed by a navigation error on a routine transit over a familiar coastline, by the ordinary operational hazard that kills men in training accidents and ferry flights, and the thousand non-combat missions that constitute most of what a wartime air crew actually does.

The submarine commanders could not reach Musen.

The cliffs of Cloverly did what they could not.

The graves at Hinton Puncheran Church are in the churchyard that looks out over the tour estie and the flat farmland leading toward the Bristol Channel.

RAF Chivvenor is still there, now a Royal Marines base.

The runways reduced and the wartime infrastructure mostly gone.

The bay that 172 Squadron’s Wellingtons crossed every night for 3 years is still there unchanged.

The same darkness in which Musen and his crews found their targets.

The hubot that crossed it after August 1943 did so, knowing that what Musen’s squadron had proven could not be unproven.

The darkness was not safe.

It had not been safe since June 3rd, 1942, when Greswell had turned on a search light over the Bay of Bisque and shown the world what 22 million candle power could do to a submarine commander’s confidence in the night.

What the Battle of the Atlantic ultimately proved was not that submarines were vulnerable or that aircraft were effective or that technology could tip tactical balances.

What it proved was that the side that could adapt its technology to the operational problem faster than the other side could counter.

The adaptation would eventually accumulate enough advantage to win.

The Yubot fleet of 1942 with its MTOX receivers and its night surface transit and its wolfpack tactics was a sophisticated and deadly system that had nearly won the campaign in the North Atlantic.

The Allied response built through three years of desperate improvisation and technical development and the operational experience of men like Musen produced a counter system that made every element of the Yubot’s advantage smaller and more expensive.

The Lee Light removed the Knight.

The sentiment radar removed the MTOX’s warning function.

The escort carriers removed the Mid-Atlantic gap.

The improved depth charges made attacks more lethal.

The support groups that could hunt submarines to exhaustion once they were detected, replaced the single escort that could only drive submarines down and move on.

Each change was small.

Together, they were overwhelming.

By the spring of 1943, the Yuboat fleet had been effectively defeated in the North Atlantic.

Not because individual submarines could no longer sink individual ships, but because the rate at which submarines were being destroyed exceeded the rate at which they could be replaced with effective crews.

What remained was the slow unwinding of a campaign that Donuts prosecuted until the end of the war, partly out of strategic obligation, and partly because admitting the defeat openly would require him to tell Hitler something Hitler did not want to hear.

Roland Musen did not live to see the full measure of what his squadron had contributed.

He had 25 days between his greatest single success and his death on a Devon hillside.

The court of inquiry that investigated the crash could not determine what had gone wrong, whether he had misread an instrument, or been given incorrect position information, or simply trusted a familiar coastline, too much in darkness and descending weather.

The inquiry found no grounds to assign blame.

It found only that a Wellington had struck high ground that should not have been there, that the crew had believed they were somewhere they were not, and that there were no survivors to explain how the error had occurred.

He was 33 years old.

He had commanded the squadron that proved the Lee Light in combat that sank six yubot in 5 months that contributed to making the summer of 1943 the turning point of the Bay campaign.

His name appears in the histories of coastal command’s contribution to the Battle of the Atlantic, usually in passing, usually attached to the sinking of U614 and the command of 172 squadron during its most productive period.

The full account of his squadron’s contribution to the campaign does not appear as frequently as the contributions of bomber command or fighter command.

Partly because the Bay of Bisque campaign was fought in darkness over empty ocean without the visual drama that makes aerial warfare memorable in photographs and film.

No photographs of the kill of U614 exist.

No footage of Musen’s attack run.

only a contact report, a postwar confirmation from German records, and a grave in a churchyard above an estie in North Devon.

The Wellington bombers of 172 squadron flew patrols across the Bay of Bisque for three more years after Musen’s death.

They sank more submarines.

They flew thousands of hours over empty ocean and returned to Chivor at dawn and refueled and rearmed and flew again.

The pilots and crews who followed Musen’s methods did not know most of the men they killed.

They saw a radar return.

They activated a search light.

They dropped depth charges.

They watched the sea erupt and then settle.

And they flew home.

The German sailors who went down with their submarines in the Bay of Bisque had names and families and histories that the air crew overhead would never know.

The nature of anti-ubmarine warfare in 1943 was that it happened in darkness in water and was confirmed only afterward by cross-referencing records that would not be fully accessible for decades.

What was accessible immediately was the result.

The convoys that crossed the Atlantic in the second half of 1943 arrived at higher rates and with lower losses than any period since the war began.

The supplies they carried sustained the Allied campaigns in North Africa, in Italy, and in the preparations for the eventual invasion of northwestern Europe.

The ships that were not sunk because yubot were being sunk in the Bay of Bisque.

The sailors who were not in lifeboats in the North Atlantic because the submarines hunting them never reached the convoy routes.

The soldiers who were supplied and equipped because the supply chain held under pressure.

These are the consequences of Lee’s search light and Musen’s squadron and the men who flew the patrols over empty ocean in darkness and did not find anything until the night they did.

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The men of coastal command are among the least celebrated of the Second World War’s air forces.

Their campaign fought in solitude over unmarked water for stakes that were immediately clear only in retrospect.

Roland Musen flew his last patrol 25 days after his greatest success and died in circumstances that had nothing to do with the enemy he had spent a year hunting.

The search light he carried changed the Atlantic War.

The cliffs of Clelli did not care.

July 30th, 1943, 047 hours, 22 million candle power over the Bay of Bisque and a submarine commander who had trusted the night for the last time.

We will see you in the next foxhole.