As you mention, the deep V hull cuts waves pretty well, but we also have algorithms monitoring the position of the boat in 3D space, looking for signals that indicate a treacherous seastate or an unfavorable position of the boat. This means that we won't do the nose dives that you see in the sailing videos.
Be sure that we have landed unexpectedly quite a few times to get to where we are! :D
To sum it up, when you are accustomed to flying with the Seven and you know where the limits are in terms of wave handling, then it's no different from riding in a regular boat in choppy seas or high waves. Unruly seas require alert sailors, in all types of boats.
We're publishing a short video soon, purely focused on running through waves from large passenger ferries. Sub to our youtube to know when.
Open water with a low probability of colliding with anything near the surface? Yeah, this looks like a blast!
Check out our videos from the Caribbean and a comparison with an 8 meter aluminum boat in a choppy archipelago condition.
Can we foil in every single wave height there is? Abosolutely not, but our boats outperform regular boats in comfort in weathers where you'd normally bring out your 8 meter daycruiser/open boat.
It's also worth remembering that in rough seas, you can go down from the foils with no issue. You just cut the efficiency down to regular boat levels...
Even if not foiling, can you still take the boat out with, say, beaufort 8-9 weather? That's more similar to what I was expecting in the "high waves" videos, and is not unusual to encounter when commuting or spending the day elsewhere, depending on your area (obviously, it starts being unpleasant if you want to spend the day at sea on a speedboat).
Edit: now realizing it, but your target market is probably only going to go out with calm weather in protected seas, given the price point and finish. I hope that sort of product will get mainstream at some point.
The reality is that it's the sea state that matters. A sheltered lake or estuary could only have 30cm waves with 40 knots of wind, whereas the open sea would have a 1.5m+ swell with 1m waves on top.
My boating skills aren't that fresh anymore, despite living on one during my childhood, and spending a good chunk of my youth close to the sea. I might thus misremember or exaggerate things, but I am fairly confident of the above.
Below that it seems to me like it behaves more or less like a regular boat. Regardless, I'd probably avoid speeds above 10 knots if I found myself in relatively high seas, and I'd just avoid going out in that kind of boat altogether if I had the option. If you do find yourself in that kind of sea though my experience is that most swells tend to come from one direction so you can find a good bearing surf the waves, zig-zagging if need be. Adjusting speed as need be is crucial in rough seas for sure.
It does have a reasonable draft without the foils extended it seems, 1 meter, and at 2.4 meters wide it seems like it could be pretty stable actually. It'll be interesting to see once my buddy gets his delivered.
I've read some on the subject, and got a book by a famous boat designer, Kotaro Horiuchi, which describes the actions of the float controllers you are talking about as well as other aspects. Foil boats have to be fairly lightweight at the moment, which is why the america's cup boats are designed the way they are.
I've also seen those e-foil surfboards but have never tried them as the price point seems absurd.
My board (and all the foils I see on surf gear) just have enhanced static stability based on some combination of dihedral, a fuselage, and a negative lift rear wing, very similar to an airplane. That's because it's down to a shift of body weight, sailing forces, etc.
It's become all the rage in the last 2-3 years with things still not quite standardized. I had to drill out my foil-approved board to get larger M10 bolts in there.
I do lurk on that forum and check out the projects people are making, there's a lot of really cool work done to 3d print propellers and other structural parts and bring the cost of manufacturing down. Between rapid prototyping and chinese BLDCs / ESCs, small electric vehicles like e-foils are actually reasonably priced to build yourself.
The dynamics of a sailing boat are far more complex than a motor boat. The drive comes from halfway up a huge lever (the mast) over the foils and its position relative to the forces produced by the foils is constantly and suddenly changing both on its own due to gusts and shifts in the wind and also caused by the sailor's inputs.
A motor boat pretty much only has to deal with going up and down over the waves.
It's like the difference between solving a linear equation and a higher order differential equation.
If you are used to it, landing unexpectedly is quite undramatic. This can happen if you foil at the lowest speed limit, or if you attempt to cross a wake or seastate that is beyond the capabilities of the boat, which is approximately 1 meter of wave height.
Water is fairly forgiving when landing unexpectedly at the speed at which the Candela Seven can operate, although you might get a bit wet.
The deep V profile the Candela's bow looks like it would handle dropping off the foil or hitting a big wave pretty well, and the 100 Hz foil control loop is reassuring, but my experience on little foiling sailboats would keep me cautious on one of these for a while. However, getting a boat to pop out above the waves is such an amazing feeling that I'd take a ride on one of these in a heartbeat (just maybe with a helmet!).
Some foiling sailboat crashes for reference -
- https://youtu.be/875yq0-ogwo?t=20
- https://youtu.be/frAkDEszgZc?t=26