The only bit of the Sailing Airship in, or anywhere near, the water is the submerged keelboard: passengers and crew are up in the sky in a sail-festooned dirigible at the other end of a cable(s).
It still mostly sails in the same manner as a ship though, poetically balancing wind against wave.
Being motorless, all maneuvering is done by careful servo positioning of sails and keelboard on their mounts.-- FlyingToaster, Apr 15 2013 Company doing kite sails http://www.skysails.com/They're using them on ships at the moment, but why not an airship? [NoOneYouKnow, Apr 18 2013] SkyTanic anchored Titanic Airship [xenzag, Apr 19 2013] Seaglider http://www.seaglide...glider_History.htmlAn attempt was made [unhelpful_fool, Jun 25 2019] Zeppy 3 https://newatlas.co...sing-attempt/15552/a Med attempt [unhelpful_fool, Jun 25 2019] Yar. (+)-- 2 fries shy of a happy meal, Apr 15 2013 I have often wondered if you could adapt a kite sail to just this purpose. That may make the keel unnecessary.-- NoOneYouKnow, Apr 18 2013 In order to go in any direction except the one the wind just happens to be moving in, you need to be connected to something else as well. On ships it's the keelboard. Same thing here except the passenger & crew, and indeed the "boat", are up in the air... guess it can't be called a "keelboard" even though that's its function.
It's a flat plate positioned vertically, though eventually some smart person would make it into a variable curve or something, to be most efficient at all speeds and angles.
It *could* be attached to the airship through a long pole, and that's easiest to visualize, but it's realistically better to use cables, and offset both sea-board and airship-sails outwards a smidge to keep them taut.
The air-sails could themselves be foisted up further into the air via cable as well, but then you'd need a mini-dirigible up there as well, to keep them from falling down in a lull.-- FlyingToaster, Apr 19 2013 //It's a flat plate positioned vertically//
I think it will have to be positioned at right angles to the cable, since it must provide a force in line with the cable. That would be easy to achieve using a pole; just a T-shaped structure, with a (non-symmetrical) hydrofoil forming the cross of the T.
(Explanation: You cannot transmit a purely horizontal force through a non-horizontal cable. There would be an unbalanced force component that would tend to lift the plate out of the water (unless it's very heavy, but that would cause other problems). A pole wouldn't help, because the whole system would rotate.)-- spidermother, Apr 19 2013 "offset from the geometry" rather than "offset from the cable".
The sea-board can be visualized as an upholstery tack: a plate with a rod in the middle. Trim tabs are needed to move it around in relation to the skyship, keep it from twisting, and are an alternative method of keeping the cable taut if you don't want to move its position.
Actually a rod system might be viable for a small ship, looking like an outrigger on a canoe, or an ice-sailer.-- FlyingToaster, Apr 22 2013 //radio, electronics and such// or whichever of the crew's in the crapper gets to ride down in a bosun's chair and keep things on an even keel manually.-- FlyingToaster, Apr 22 2013 Stephane Rousson attempted something like this and was going to attempt an Atlantic Crossing. For reasons, it seems as though he did not go through with it.-- unhelpful_fool, Jun 25 2019 // In order to go in any direction except the one the wind just happens to be moving in, you need to be connected to something else as well. //
Your keel doesn't necessarily need to be in the water. It could be in the air, at another altitude, where the wind is blowing in a different direction. You could call it a Sky Keel or something. It also approaches another idea that's on my list to post (since years ago), but I don't think it reveals too much yet.-- notexactly, Jul 21 2019 random, halfbakery