Glossary of Sealion Threads

In daylight, the Royal Navy would have suffered some losses. At night, very few. Plus the Navy would have fighter escorts much of the time. The Luftwaffe might have been able to drive 11 Group from the sector stations south of the Thames but not prevent the squadrons being based elsewhere and using airfields in the south to refuel and rearm.

Stukas attacking RN warships are Stukas not providing CAS to the Heer ashore. And in either role are extremely vulnerable.
But in Crete, the Lutwaffe had a different primary task and that was to support the airborne units. Most air operations were aimed at capturing the island. Attacking RN ships was a secondary objective. Furthermore, the strength of the Luftwaffe was very limited, some reasons:

1. poor airfields in the area, moreover there were few, which reduced the strength of the Luftwaffe in the area
2. lack of fuel, if the Germans had not recovered the supplies of aviation gasoline left here by the RAF, their air operations would have been further curtailed
3. unsuitable aircraft, much of the attack on RN ships was carried out by Do 17's which had a small bomb load, in addition they carried out their attacks from higher altitudes
4. poor infrastructure in Greece, which made it difficult to supply the Luftwaffe, resulting in fuel and bomb shortages
5. the long distance between the targets, which did not allow the full potential of the Ju 87 to be used, which mostly used only SC 250 bombs, only rarely were heavier ones used

All very well described in this book: (

Airfields in France would be much better supplied, closer to the operational areas, and the Luftwaffe strength would be much greater. Units equipped with the Ju 87 could use much heavier and more effective bombs than just the SC 250. British losses would certainly not be small as you claim….

1- I didn't give any indication that the losses would be "small" - in fact I specifically said that at Crete the losses were "severe". I don't think they would be small, but I don't think the LW would be able to stop the RN from largely interdicting convoys - and I don't think any reasonable modern source thinks it either.

2- I don't have the book you mentioned and can't find any information on what proportion of LW effort at the evacuation of Greece and Crete went into the naval battle versus the land one.

3- LW strength would be greater in the Channel but so would RAF strength.

4- The LW would be closer to its bases but so would the RN. At Crete the RN was operating so far from its supplies that there was a significant problem with ships running low on AA ammunition, which would not be a problem in the Channel.

I can't find an order of battle for the LW in detail, but a 1960 study states that Fliegerkorps VIII had "716 aircraft" with "514 were reported serviceable on 17 th May. They consisted of:— 228 bombers. 205 dive bombers. 114 twin engined fighters. 119 single engined fighters." As far as I can see, that's about half as many aircraft as most sources say would have been available for Sea Lion.

At Crete the RN lost three cruisers and six destroyers, plus some of the small craft of the Suda Bay base force (many of which were scuttled). That's a "sinking rate" of 0% of battleships, 0% of carriers, 27% of cruisers, 19% of destroyers, and 0% of the few small convoy escorts. If we assume that at Sealion the LW forces, being double the size, manage to sink double the percentage of British ships then they'll sink half the cruisers, leaving three; 19 destroyers, leaving 48. That's ignoring the 34 sloops and corvettes and the 165 minesweepers.

Yes, some other vessels would be damaged but given the crisis that Sealion would represent, many damaged ships would stay in the fight. At Crete there were seven destroyers damaged but most of those damaged could have kept on fighting effectively; for example HMAS Napier could still steam at 23 knots and appears to have retained full firepower; HMS Kelvin was in a similar position but reduced to 20 knots; HMAS Nizam is listed as damaged but doesn't seem to have been out of service at any time. Two of the battleships received serious damage as did some of the cruisers but there's probably a 50% chance that Revenge can stay in the fight.

When the Home Fleet came south there'd be some fraction of another five capital ships, 18 cruisers, 35 destroyers and perhaps even the two carriers. Then there'd be ships withdrawn from Western Approaches Command. So once the reinforcements arrived the RN would be stronger than before the battle, given historical loss rates.

5- In Sealion the LW also had to support the land forces just as in Crete, so there's no difference there.

6- As Finnbar points out, the RN would have suffered very little loss from the LW at night, which would allow them to range quite freely and cause havoc among convoys sitting off the English coast.

Basically, those who claim the LW would have wiped out the RN, or come close to it, are ignoring the historical evidence. We see a lot of that in forums; for example in one Sealion thread someone pointed out the sinking of Yamata, PoW and Repulse but looking at isolated incidents like that ignores the many, many actions were the air was unable to severely harm naval forces. We tend to look at the sinkings but ignore the times when nothing like that occurred, yet the sinkings are the outliers.
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It's also worth noting that in Crete many ships ended up low on AA ammunition. Working much closer to bases, RN units will be more easily supplied so this problem will be reduced (though probably not eliminated entirely). They will also be supported by the RAF and by any heavy AA near the shore, so Crete is likely a worse case than Sealion.
As for sinking the RN, the majority of initial anti-invasion fleet duties will be by the lighter forces in the immediate area. These lighter vessels are potentially more vulnerable to damage from bombing but are small targets that are not necessarily readily distinguished from invasion vessels from altitude in daytime [1]. The best chance to hit these is by strafing - which takes fighters out of fending off the RAF - or by dive bombing, using stukas which were very vulnerable without fighter protection. Level bombing would be disruptive, but is notoriously inaccurate against moving targets and is even more likely to involve misidentification of targets due to higher altitudes.
While at least some of the lighter vessels were armed trawlers etc, even these typically had at least some trained gunners on board (I can't find the reference right now as it wasn't where I thought). RN light vessels typically included light AA weapons with fully trained crews, as well as being very well equipped to attack naval and other vessels (twin 6 pounders would mince any barge, as would the 3" guns).

[1] Destroyers yes, but the other light vessels - armed trawlers, gunboats etc - would look quite similar to German vessels from a few thousand feet.
It's interesting to see that the thread with the glossary of Sealion threads is now used to redo the arguments in the Sealionthreads it refers to.
What about if Sealion was launched from the Frisian Islands? After all, they are the best way into Germany so logically they are the best way out of it. (Ducks and runs for cover)
What about if Sealion was launched from the Frisian Islands? After all, they are the best way into Germany so logically they are the best way out of it. (Ducks and runs for cover)
x'D x'D

It would also means covering an ever greater distance over open water... I almost pity the german troops in their towed barges. Almost.
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Would a thread on the Soviets joining in the air campaign against the UK (assuming that the Western Allies came into conflict with the Soviets, say in Finland or something) be considered too sea lion like for the forum? I'm not asking if they could successfully invade, merely asking what the effect would be of Soviet air assets, and naval, I suppose, being available for operations in tandem with Nazi Germany?
It's not like Sea Lion, but it would require a major POD, like the death of Stalin, followed by some very complicated follow-ons. It could probably be made plausible but my mind goes blank on that. I can actually see the Soviets under new leadership not attacking Finland at all, and then winning the Siege of Leningrad sooner.
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Well there is the possibility that the Allies follow on with their OTL plans to bomb the Baku oil fields and sent aid to Finland by invading Norway and Sweden, which would consequently forced the USSR to join the Axis powers and declare war on the Allies.

Although realistically Hitler wanted his lebensraum and would not be happy to accept the "inferior" Soviets into the Axis powers, so a lasting Berlin-Moscow Axis will be only achieved if one of the failed attempts to assassinate Hitler is successful and Göring is subsequently able to acquire enough power to become the new Führer, since Göring opposed invasion of USSR and would rather have them be allied to Germany.

Stalin meanwhile wanted to have the Fascist Germans and Anglo-French Imperialist powers to wear themselves out from fighting against each other, while he invaded Turkey, Afghanistan, Iran and influence the Middle East, before finally having the Red Army invade and conquer a heavily weakened Europe. These plans of course quickly fell apart after Nazi Germany shocked the world by easily conquering France.

Stalin in this scenario is fighting a war with the British Empire and has to worry about the borders of Turkey and Iran while also dealing with the threat of the British forces based India, So I doubt Stalin will really want to risk gambling his chances of winning the war against the Allies by betraying the Germans.

The scenario would need muliple PODs and follow on's of course but it can be made plausible.
22000 Kevin, you have here a Scandinavian military alliance (made possible if the British Navy and its carriers can crush the German invasion of Norway and later create a allied military front stretching from Norway to Finland). This depends of course on a weak reed--the French being better prepared and with better generals for the war and thus no easy victory for Hitler.

Second you have the disparate issue of the Great Game, Czarist Russia's scheme for keeping the British out of Central Asia and seizing Himalayan outposts preliminary to swooping into India (there was a clique within Soviet intelligence that was also intrigued with this idea in the interwar period, believing there was a secret Buddhist wisdom center that would be a key to the domination of Asia).

What is the connection? Mannerheim, the military leader of Finland in World War Two, had, as a Czarist military officer, been a master spy of the Great Game, partly under cover as an ethnologist and reporting to the Czar himself.

How to link these two disparate themes, which both connect in so many ways with your POD speculations above? Read Mannerheim's Wikipedia bio Pay special attention to the section "Service in the Imperial Russian Army" (see below). You'll be amazed at the weird possibilities.

Service in the Imperial Russian Army[from Wikipedia]​

Mannerheim served in the Imperial Chevalier Guard until 1904. In 1896, he took part in the coronation of Emperor Nicholas II, standing for four hours in his full-dress Imperial Chevalier Guard uniform at the bottom of the steps leading up to the imperial throne.[29] Mannerheim always considered the coronation a high-point of his life, recalling with pride his role in what he called an "indescribably magnificent" coronation.[29] An expert rider and trained horseman, Mannerheim bought horses for the Russian army as one of his official duties. In 1903, he was put in charge of the model squadron in the Imperial Chevalier Guard and became a member of the equestrian training board of the cavalry regiments.[30]

After his coronation, Nicholas II of Russia leaves Dormition Cathedral. The Chevalier Guard Lieutenant marching in front to the Tsar's left (to the viewer's right) is Mannerheim.

Mannerheim volunteered for active service with the Imperial Russian Army in the Russo-Japanese War in 1904. He was transferred to the 52nd Nezhin Dragoon Regiment in Manchuria, with the rank of Lieutenant-Colonel. During a reconnaissance patrol on the plains of Manchuria, he first saw action in a skirmish and had his horse shot out from under him.[29] He was promoted to Colonel for bravery in the Battle of Mukden in 1905[31] and briefly commanded an irregular unit of Hong Huzi, a local militia, on an exploratory mission into Inner Mongolia.[32] During the war, Mannerheim also managed to lead a group of local thugs and crooks with whom he sought the back of the enemy to defeat them.[33]

Mannerheim, who had a long career in the Imperial Russian army, also rose to become a courtier of Emperor of all the Russias Nicholas II.[33] When Mannerheim returned to Saint Petersburg, he was asked to undertake a journey through Turkestan to Beijing as a secret intelligence officer. The Russian General Staff wanted accurate, on-the-ground intelligence about the reforms and activities by the Qing dynasty, as well as the military feasibility of invading Western China: a possible move in their struggle with Britain for control of inner Asia.[34][35] Disguised as an ethnographic collector, he joined the French archeologist Paul Pelliot's expedition at Samarkand in Russian Turkestan (now Uzbekistan). They started from the terminus of the Trans-Caspian Railway in Andijan in July 1906, but Mannerheim quarreled with Pelliot,[34] so he made the greater part of the expedition on his own.[36]

Gustaf Mannerheim's route across Asia from Saint Petersburg to Peking, 1906–1908.[37]

With a small caravan, including a Cossack guide, Chinese interpreter, and Uyghur cook, Mannerheim first trekked to Khotan in search of British and Japanese spies. After returning to Kashgar, he headed north into the Tian Shan range, surveying passes and gauging the stances of the tribes towards the Han Chinese. Mannerheim arrived in the provincial capital of Urumqi, and then headed east into Gansu province. At the sacred Buddhist mountain of Mount Wutai in Shanxi province, Mannerheim met the 13th Dalai Lama of Tibet. He showed the Dalai Lama how to use a pistol.[38]

He followed the Great Wall of China, and investigated a mysterious tribe known as Yugurs.[39] From Lanzhou, the provincial capital, Mannerheim headed south into Tibetan territory and visited the lamasery of Labrang, where he was stoned by xenophobic monks.[40] During his trip to Tibet in 1908 Mannerheim became the third European who had met with the Dalai Lama.[41] Mannerheim arrived in Beijing in July 1908, returning to Saint Petersburg via Japan and the Trans-Siberian Express. His report gave a detailed account of Chinese modernization, covering education, military reforms, colonization of ethnic borderlands, mining and industry, railway construction, the influence of Japan, and opium smoking.[40] He also discussed the possibility of a Russian invasion of Xinjiang, and Xinjiang's possible role as a bargaining chip in a putative future war with China.[42] His trip through Asia left him with a lifelong love of Asian art, which he thereafter collected.[38]

After returning to Russia in 1909 from the expedition, Mannerheim presented its results to the emperor to which Nicholas II listened with interest. There are many artifacts still on display in the museum.[33] After that, Mannerheim was appointed to command the 13th Vladimir Uhlan Regiment in the Congress Kingdom of Poland. The following year, he was promoted to major general and was posted as the commander of the Life Guard Uhlan Regiment of His Imperial Majesty in Warsaw. Next Mannerheim became part of the Imperial entourage and was appointed to command a cavalry brigade.[43]

At the beginning of World War I, Mannerheim served as commander of the Separate Guards Cavalry Brigade (the 23rd Army Corps), and fought on the Austro-Hungarian and Romanian fronts. In December 1914, after distinguishing himself in combat against the Austro-Hungarian forces, Mannerheim was awarded the Order of St. George, 4th class. In March 1915, Mannerheim was appointed to command the 12th Cavalry Division.[44]

Mannerheim received leave to visit Finland and Saint Petersburg in early 1917 and witnessed the outbreak of the February Revolution. After returning to the front, he was promoted to lieutenant general in April 1917 (the promotion was backdated to February 1915), and took command of the 6th Cavalry Corps in the summer of 1917. However, Mannerheim fell out of favour with the new government, who regarded him as not supporting the revolution, and was relieved of his duties. He retired and returned to Finland.[43] Mannerheim kept a large portrait of Emperor Nicholas II in the living room of his house in Helsinki right up to his death, and when asked after the overthrow of the House of Romanov why he kept the portrait up, he always answered: "He was my emperor".[38]
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Monthly Donor
Would a thread on the Soviets joining in the air campaign against the UK (assuming that the Western Allies came into conflict with the Soviets, say in Finland or something) be considered too sea lion like for the forum? I'm not asking if they could successfully invade, merely asking what the effect would be of Soviet air assets, and naval, I suppose, being available for operations in tandem with Nazi Germany?
THis is a thread dedicated to Sea Lion threads. Please do not use it for other discussions.