[Hayseed (OP)]

What if we could permanently place an air blanket on the hull?  The smooth surface of a bubble should have little drag.  Maybe a continuous disposable bubble.

Would graphene drag?  Perhaps a graphene balloon for a blanket.

[chiralSPO]

What if we could permanently place an air blanket on the hull?  The smooth surface of a bubble should have little drag.  Maybe a continuous disposable bubble.

Would graphene drag?  Perhaps a graphene balloon for a blanket.

Interesting approach to reducing drag... (I have split this off into a new thread because it was only tangentially related to the OP of the first thread it appeared in)

I wonder how the energy would compare between a hovercraft, vs just superheating the surface of the ship and using the Leidenfrost effect (https://en.wikipedia.org/wiki/Leidenfrost_effect). Presumably much more energy used to boil water than blow air, but not having any moving parts could make it easier to maintain (plus no barnacles!)

Best option is probably to use a superhydrophobic coating, but that could be very expensive (capex, not opex) and I don't know how well it would last...

[alancalverd]

Various navies have tried using bubbles, soft skins, and even eel-like artificial slime, to increase hull speed. AFAIK the result always suggests that you could get there quicker, with less power, in an aeroplane. It seems that the Solent hovercraft are the only survivors of what looked like an excellent technology - I guess the hydrofoil turned out to be more weatherproof for the same speed/power ratio, and the cost of training and retaining civilian hovercraft pilots and engineers (who, thanks to the Powers that Be, have to have both commercial aircraft and marine certificates) makes commercial operations very difficult.

[evan_au]

I took the hovercraft between Calais and Dover several times, before it was rendered obsolete by the Channel Tunnel (or "Chunnel"). The hovercraft certainly had a weird motion in the sea.

Today, icebreakers use pressurized air to help them through the ice.
And some speedboat designs trap a bubble of air under twin hulls to help lift them out of the water.

[Hayseed (OP)]

All righty then.  The advantage of a ship transport is not time, it's mass.  That could change.

An air boundary/interface will increase speed, but the pay-off is less propulsion energy cost.  I think I read of 200 MPH torpedo speed.  That was preliminary and dated. With greater speeds expected.  The torpedo is moving thru air, around the torpedo. Like a airplane.  The research is probably proprietary now.  Or dismissed, if you believe that.  How about a cargo size torpedo?  And autonomous.

Less energy consumption and exhaust products for the hysterical intellects.  For the non-hysterical, we could ship large amounts of crude(or other products).....anywhere in the would....in hours, not days and weeks.  Sorta like an amazon prime account for fossil fuels.  Or other large mass cargo, lumber, stone etc.  Even fresh water.

I hadn't thought of boiling.  Maybe a thin graphene skin could be heated at little cost.

Or maybe a graphene structure that has a "aerophilic" property with an air bubble.  And as a added bonus.....prevent parasitic growth.