I agree the wave action is less below the surface. Lets say you have 5ft waves, which are really common on the ocean. And you have a business owner out to see how the submarine rides. I cannot imagine how you will convince the business to deal with going from bouncing boat to stable submarine, and climb down inside sail with his employees, and then when waves go to 10ft he must close the hatch and stay inside for 3 or 4 days or a week?
I think this is very important point: if you are in the wave zone, even with submarine “sail”, waves will be a problem, I just now checked global wave map, and north of the equator there is now more 20ft/6m waves than smaller waves. And i think if the sail is not submerged also, the 20ft/6m waves WILL push it over, and make the submarine lean. Under these conditions, the business will be trapped under water until the waves go down, and they will not have customers visit (how will they get in or leave?).
Somebody still have to explain to me how this seawall is going to work….Since we are talking about a floating city, it means that the seawall is connected to the city itself, part of the whole structure? Otherwise, if free floating it will collide w/the city at some point.
If part of the structure, than the cost and engineering challenges of a 20 mile seawall built as a ring around the whole structure will be huge!! Can you imagine what will happen to the seawall in a category 2-3 hurricane (forget about 4-5)? Is gonna be pounded so badly by the waves, and flex big time. High probability is that will break and breach here in there. I have big doubts about how feasible and functional such seawall is going to be…
My view is that for large floating seasteading projects (floating islands, cities, etc) you need high strength concrete modular platforms with much higher than usual freeboard, variable draft capable and built like a tank with multiple collision bulkheads. They should have their own power and able to detach from the raft up formation and ride storms by themselves. Also, the geometric shape of the platform is very important, since they cannot be built based on nowadays ship’s design (they are seasteads :). The best design it’s a kite shaped structure, as presented in a project of mine 5 years ago.
Most of the tragic accidents related to freak waves hitting vessels seem to have happened when those waves hit them broadside (perpendicular to the sides of the ship, port or starboard) and they capsize. It is like hitting a wall. That’s where the problem is…
A kite shaped design (4 corners) will cut into a waves (freak or otherwise) when hit broadside, thus highly reducing the force and momentum on impact. Yes, there is still a chance to get hit on the both quarters or bows (45 degrees port or starboard), but it is a smaller surface (half compared to a rectangle of the same length) and it is angled.
…this is a huge project with huge upfront money requirement, where should that money come from ? 160.000 tons of concrete … with a parkhouse and shopping mall inside. Big enough to dock 4 cruiseships on it.
For a small scale startup you really need to plan something different than enclose cities in floating walls…Monaco can afford a small piece of such a wall – but who else can?