I understand that seaplanes are usually prop planes but for cargo planes it would be beneficial in times where large cargo supply operations need to be carried out on non-carrier operations.

  • $\begingroup$ warontherocks.com/2020/07/bring-back-the-seaplane $\endgroup$
    – Krazy Glew
    Nov 22, 2021 at 1:38
  • 1
    $\begingroup$ If you want to see examples of commercially successful large seaplanes google Saunders-Roe. They were the kings of seaplanes in the 40s and 50s. By the 1960s they shut down. $\endgroup$
    – slebetman
    Nov 28, 2021 at 9:54

4 Answers 4


Because you can't land a seaplane at high seas anyway. Seaplanes can't handle too big waves.

It is said that hitting water at high speed is just like hitting concrete (at somewhat slower, but still quite high speed). The landing has to be gentle for the sea plane to handle it (about similar to landing on the land). But if there are significant waves, the aircraft touches down, bounces of the next wave and then will hit the next one at too steep angle and be damaged or destroyed.

With early float biplanes that had landing speed maybe 20 or 30 knots it could work, and they were sometimes used as observation planes launched with catapult and then landing on the water next to the launching ship. But today wherever slow speed is enough, a helicopter is more practical, and when high speed is needed, it wouldn't work.

And the Navy did try with Convair F2Y Sea Dart, and it proved impractical. It was also other parts of that design that were unsatisfactory, but nobody ever try the water skis again because they didn't show enough advantage to be worth it.

Also Russian Navy tried with Beriev A-40 Albatros, with original intent as maritime patrol aircraft, but the only version that entered production is the civilian Beriev Be-200 Altair used mainly for aerial fire-fighting.

  • $\begingroup$ In a comic series called Tintin, he used a catapult seaplane but if you look at the Boeing Pelican Prototype, I believe there could very well have been a seaplane variant $\endgroup$ Nov 19, 2021 at 17:56
  • 3
    $\begingroup$ And now they have the V-22 Osprey anyway, which covers all the space a naval cargo seaplane might. $\endgroup$ Nov 20, 2021 at 0:18
  • 2
    $\begingroup$ @Harper-ReinstateMonica, indeed. And I didn't think it would, but a V-22 has double the payload compared to C-2 Greyhound, so it certainly solves the problem pretty well. $\endgroup$
    – Jan Hudec
    Nov 20, 2021 at 12:48

The real answer is because there is no need.

Prior to WW2, both the US Navy and US Army had huge interest in seaplanes for exactly the reason you mentioned: large cargo supply operations. Indeed, it was not only the military who were interested. Commercial civil aviation was also hugely interested in seaplanes. The period in history that saw the success of large seaplanes was exactly at the beginning of WW2.

WW2 had a very interesting side-effect to aviation. Because aviation was so important in the war effort the war caused thousands of airfields to be constructed. After the war a lot of these airfields evolved into airports (both military and civillian). Airports killed seaplanes. The main advantage of a seaplane is being able to operate without an airport. If you have an airport you don't need seaplanes.

WW2 also taught militaries around the world the importance of combined arms and cooperation between all the different forces you own. For the US military transport operations are primarily the responsibility of the Air Force. So the reason why the Navy does not do large cargo supply operations is because that is the job of the Air Transport Command which is part of the Air Force. And the US Air Force does not want to use seaplanes to transport cargo because they have airbases all over the world.

There is practically no location on Earth near a large body of water that is not also near an airport or airfield.

  • $\begingroup$ How about small bodies of water- any where not near an airport or airfield? $\endgroup$ Nov 20, 2021 at 9:58
  • 2
    $\begingroup$ @user2617804 The US Navy does not operate inland. That's the domain of the Army and they have Chinooks and Blackhawks for such operations so they don't need the small body of water when they can land cargo directly on mountaintops. $\endgroup$
    – slebetman
    Nov 20, 2021 at 14:20
  • 1
    $\begingroup$ What fraction of islands and atolls in the Pacific have airstrips large enough for big cargo aircraft like the C5 Galaxy? What fraction of the water in such island chains? I think you meant to say “no LAND location on Earth near a large body of water is not also near an airfield”, since not true for ocean surface, which by definition are near, actually part of, a large body of water. $\endgroup$
    – Krazy Glew
    Nov 22, 2021 at 2:08
  • $\begingroup$ They can also land C130s and C-5 galaxies on relatively flat terrain on short runways as well as beaches. There was an operation to rescue hostages in Iran that had 4 c130s fly ahead to refuel helicopters on the ground. $\endgroup$
    – Olaf
    Nov 22, 2021 at 7:13
  • 1
    $\begingroup$ @BobJarvis-ReinstateMonica The C130 can't quite cover Pacific operations. The C17 Globemaster however can fly from the continental US to Hawaii and from Hawaii to either mainland Asia or New Zealand. It can also operate from almost any airfield the C130 can $\endgroup$
    – slebetman
    Nov 22, 2021 at 15:02

In addition to Jan's answer, to recover the aircraft you need to slow down, nearly stopped. This makes the entire ship group vulnerable.

Also, an aircraft carrier can recover aircraft at full speed and have multiple launch/recovery operations running at the same time. Swapping out a flight of aircraft takes minutes.

For cargo operations this is called "replenishment at sea" and there is a well defined method to carry that out without stopping or slowing down much.

  • 7
    $\begingroup$ My understanding was that carriers actually prefer to be moving during launch & recovery, since sailing upwind increases the airspeed relative to the deck. $\endgroup$ Nov 20, 2021 at 14:02
  • 8
    $\begingroup$ @MichaelSeifert Not just preferred, they are required to. Landing speed would be way too fast if the carrier were stopped, the arresting gear wouldn't be able to stop the aircraft. That 30+ knots of speed means a lot. $\endgroup$
    – Ron Beyer
    Nov 20, 2021 at 15:37
  • $\begingroup$ Para 1: It took a couple reads of the first paragraph to realize you meant to recover the seaplane. (I thought at first this contradicted para 2) Consider clarifying. Para 3: The Navy actually calls it UNREP, for Underway Replenishment of fuel via hoses between ships, or VERTREP, for Vertical Replenishment for helo transport of cargo. The COD is just the COD, I have never heard it referred to in more formal terms as you described it. Your comment: I believe the C2 can recover with very a slight tailwind. (I can verify if needed...) $\endgroup$ Nov 23, 2021 at 2:54

I had about 1,800 pilot hours in seaplanes. Seaplane ops were very costly in equipment and manpower plus the eventual salt-water damage to the planes. The sooner we could end those ops the better.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .