Warwick wrote:

… uh-oh… sounds like you’re going to try to cut in on my market for fusion-powered airships… Let the first fusion-powered trade war commence! 😉

Yeah I much favour marine transport over air transport. It’s a lot more aesthetic. And I hate flying. Would a fusion powered airship be feasible? (Are there battery-powered electric motor-driven aircraft of any description at present?)

Yes and yes… manned aircraft have flown propelled by solar, by fuel cell and even by AA batteries 🙂

http://en.wikipedia.org/wiki/Electric_aircraft

This thread has a lot of relevant comments and speculation about fusion-powered aircraft, even when sidetracked by the seemingly inevitable digression in fusion-powered spaceflight…

https://focusfusion.org/index.php/forums/viewthread/560/

(note to self: start thread on fusion-powered tunneling machine and record time until first comment about its potential as a launch vehicle..)

(… I never did get back to that thread… got distracted by a claim that the waste heat from an FF plant would limit its distribution in urban environments… which turned out to be a non-issue when the FF unit was allowed to spare 3 or 4 dozen kilowatts for heat dissipation…)

It turns out that basic 5 MWe FF units would do nicely as substitute power sources for a variety of turboprops and turbofans, but volume constraints in tube-and-wing aircraft designs are a bit of a pain. Airships would not have those constraints.

As for air ship vs ocean ship…

The first thing that leaps out is your assumption of ship speed: 200 mph would be 173 knots. That’s in comparison to the U.S. Navy’s fastest admitted speed of “above 50 knots” for an experimental ship. Now the [em]actual[/em] top Navy speed may well be in excess of 70 knots… 80.5 mph… but at 173 knots that’s not a ship anymore, that’s a loitering ekranoplane 🙂

The primary historical drawback of airships, their vulnerability in the air/ground interface, has been mitigated by modern design techniques that essentially turn them into heavier-than-air ships during takeoff and landing while still allowing them to keep their VTOL capabilities. With these modern design features a variety of large airships have been proposed that exceed speeds of 115 knots and altitudes in excess of 30,000 feet… and that’s before factoring fusion power plants into the designs and fusion would be be especially helpful here with its power availability and no fuel constraints.

So with that in mind I think that fusion-powered airships would beat fusion-powered ocean ships for passenger travel. The airships would be both faster and more comfortable with no swaying decks and the ability to fly above most inclement weather. They would not be limited to coastal ports and could land and take off almost anywhere. And if the weather was good they could sail 50 feet above the ocean surface and get the whole cruse ship vibe going… without seasickness 🙂