Inflatable sail kite, lighter than air to pull boat forward.

I know they have those things.
Simply deploy off the bow, it floats up, and grabs the wind and powers the boat ahead. Might be good when going on a long ocean voyage with the trade winds.

My dock-neighbor has a Island Packet 35 Catamaran, and he often sails it with a parachute in that manner. He has the chute rigged to the mast somehow, and in the right direction, with the right winds, it works perfectly.

Most boats do not have the scantlings for "long ocean voyage with the trade winds".


Most of the ones that do are called sailboats.

At first I didn't realize what I was looking at as we were leaving St. Maarten several years ago. By the time I got the camera out, she had blown by us. The kite was on a power cat of about 40'. I’ve no idea if it was inflatable or not but still pretty cool.

About 50 years ago some one asked the AYRS (Amateur Yacht Research Society) im GB


"what is the most efficient yacht"

Their response was a submarine , towed by a box kite.

Larry M said:

At first I didn't realize what I was looking at as we were leaving St. Maarten several years ago. By the time I got the camera out, she had blown by us. The kite was on a power cat of about 40'. I’ve no idea if it was inflatable or not but still pretty cool.

Click to expand...

Oceansails still sells them (see Google). We're looking at one for a 50' power cat we're purchasing. Many of the other manufacturers for kites for yachts sem to have gone (Dave Culp etc.). The boat in the pics was almost certainly the Lagoon 43.

I suppose it's practical if often one's course is extensively downwind.

markpierce said:

I suppose it's practical if often one's course is extensively downwind.

Click to expand...

True flown from a powerboat. OTOH, foiling kite boards are currently the fastest sail powered craft upwind, in VMG.

markpierce said:

I suppose it's practical if often one's course is extensively downwind.

Click to expand...

Most of the world cruising is purposely downwind - planned that way for the obvious reasons that it's not great for a power OR sail boat crashing to windward for days on end. It's clearly not true for certain more limited places or latitudes of course.

The claim for that particular kite (or chute) is that it's effective for winds 45 degrees either side of astern. That's a pretty wide range of conditions if you choose your cruising times. Of course with a power boat (nee trawler) you can always just turn on the engines, catering happily to the percentage of time the wind isn't blowing, is blowing too much, or isn't blowing in the right direction, or when you simply want to hear that deep rumble and smell the diesel . Each to their own .

Seems like an excellent item to keep for emergency propulsion for single engine boats. Even if it only pulls your 50ft trawler at 1 knot that certainly is better than sitting dead in the ocean.

Someone on this forum has to own a kite board - it would make a great experiment to see how well your trawler is pulled along.

makobuilders said:

Seems like an excellent item to keep for emergency propulsion for single engine boats. Even if it only pulls your 50ft trawler at 1 knot that certainly is better than sitting dead in the ocean.

Someone on this forum has to own a kite board - it would make a great experiment to see how well your trawler is pulled along.

Click to expand...

My "emergency power" is the (3)VHF radio or Cell phone or Sat phone.

On a 34ft trawler, there isn't much room to store 'stuff'. If I had a bigger boat, I would take stuff out of the store room and put it on board.

OldDan1943 said:

My "emergency power" is the (3)VHF radio or Cell phone or Sat phone...

Click to expand...

Lots of boats on this coast have 9.9hp outboard kickers on the swim step...no tow service and the nearest boat might be over four hours away.

Long inlets with inflow/outflow winds would make a kite useful, but raises a few concerns.

We used to use a parafoil kite to pull our sea kayaks. It was fun with 20 knot winds but a white knuckling experience at 25 and over. A knife at the ready to cut the line was a blatantly obvious idea. On a trawler you would have to have some sort of quick release mechanism to cut the kite loose in emergencies.

Also, if the kite is taking some load off the engine, would this have any negative effects on the engine if you were running downwind all day?

There was an episode of “The Last Ship” where they used kites to sail the ship.

MurrayM said:

...Also, if the kite is taking some load off the engine, would this have any negative effects on the engine if you were running downwind all day?

Click to expand...

There's the potential of problems with the cutlass bearing and transmission if the prop is left spinning without the expecting cooling/lubricating circulation that might otherwise occur when under engine power. I'd imagine this varies from one design to another, but it'd be something to confirm before incurring repair expenses...

The big guys use them for fuel savings




https://www.skysails.info/index.php?L=1

markpierce said:

I suppose it's practical if often one's course is extensively downwind.

Click to expand...

That's the way sailors try and do it. Beating to windward is not much fun in anything.

The utility is far less then it seems.

The wind is seldom that steady. It may seem so, but with a wind instrument that has max and min telltales, one can see that even "steady" at 20 kts, will have a range of maybe 5 to 25 over time.

For a power boat, when the wind dies suddenly, running over your kite, will kill any advantage you gained.

Wxx3 said:

...For a power boat, when the wind dies suddenly, running over your kite, will kill any advantage you gained.

Click to expand...

And then there's all that line in the water that you're about to run over with a heavy water filled bundle of fabric at the end of it.

For those on another thread that wanted to know how to stop "hunting" at anchor, this may be a solution (flown aft)

Wxx3 said:

The utility is far less then it seems.

The wind is seldom that steady. It may seem so, but with a wind instrument that has max and min telltales, one can see that even "steady" at 20 kts, will have a range of maybe 5 to 25 over time.

For a power boat, when the wind dies suddenly, running over your kite, will kill any advantage you gained.

Click to expand...

While true at sea level and near, it is not true at a height above (100-200' for example) the water. It is usually remarkably more clean, although it may also be in a different direction and a very different strength! Your windspeed indicator is useless at gauging this (unless you have a remarkably high mast ).

Have not used a sail with a board in a long time, but I enjoy watching the people using kites in our area. It is truly amazing the speed they generate, but a lot of forces being generated so there is a risk to reward factor involved. It looks to be more a novelty for boats, but a cool one.