We are working on a seastead design. Above the water there will be a big triangle frame. The left and right sides will be 70 feet long and the back part of the triangle will be 35 feet wide. The point opposite the 35 ft side is the front. The triangle frame will be a truss structure that is 7 feet high (floor to ceiling). It will be enclosed and the whole inside the living area. Lots of glass to see out. There are 3 legs/floats/foils/wings that provide the buoyancy, so it is a bit like a trimaran but with a very soft ride. Each leg/wing will 19 feet long and have a NACA 0030 foil shape with 10 foot chord and 3 foot width. Each of the 3 legs will be attached to the underside of the big triangle near one of the 3 points (but the total top of the leg will be inside the triangle) and going down so that the lower half is in the water. This makes for a "small waterline area" similar like a small oil platform but one that can move through the water easier because of the foil shape. The 3 legs will all be parallel with the blunt or "leading edge of the wing" side facing forward so it is low drag for the seastead to move forward. Each leg will be 50% under the water (so 0.5 * 19 feet) and the top 50% out of the water. On the top half of the front of each leg, so the top half that is out of the water, will be a built in ladder. There will be 6 RIM drive thrusters of 1.5 foot diameter, one on each side of the 3 legs/wings about 3 feet up from the bottom. These RIM drives will have the flat sides toward the front and back of the seastead. On top of the roof there will be solar all over. Behind the back near the center will be two supports going out and 2 ropes going down to a dinghy. The dinghy is a 14 foot RIB boat with an electric Yamaha HARMO outboard. It is sideways against the center of the backside of the living area. When the seastead is moving forward the dingy is shielded from the wind by the living area. Also behind the back on the left and right of the dinghy will be a deck that is 5 feet wide extending beyond the back of the triangle. There are 3 stabilizers that look like a little airplanes, one attached near the back of each main seastead leg. The little airplane has a 12 foot wing-span, 1.5 foot chord, the body 6 feet long, and the elevator has a 2 foot wing-span and 6 inch chord. A small actuator makes the elevator angle up or down so it can adjust the angle of attack of the main wing of this stabilizer without needing a large actuator. This is really the "servo tab" idea. While the thick part of the leg is 3 feet wide the back where the airplane will attach is very thin. And to get the airplane's center of lift to balance on the pivot a notch into the front/center of the wing only has to go about 25% of the chord of the wing. When the seastead is going to be staying in one place for awhile, we can put down 3 helical mooring screws and give the seastead tension legs so it becomes nearly stationary when parked. Two seasteads will be able to connect together with a walkway, one behind the other, so that while underway people can move between seasteads, enabling a real community. About my biggest concern with this tensegrity design is the risk of waves making cables go slack and then suddenly snap tight and break, the "snatch load" issue. For example, waves on two opposite corners might suddenly lift up the legs on those corners so the other two legs cables went slack, then if it suddenly drops back the other two legs could get a sudden load. I am not certain how much of an issue this is for real waves. Small waves just won't be able to put enough extra lift on some floats fast enough to make the cables for another float go slack. Normally the bigger the wave the more all of the floats are feeling the same part of the wave, say a long-period swell. Can you tell if there could be Caribbean waves (non-hurricane) that could actually make one of the cables go slack? Like perhaps it requires a 20 foot breaking wave and we can't get those in the Caribbean without a hurricane. Each float has a lot of lifting force pulling on the float cables, so it is not easy to make it go slack in normal Caribbean waves. For now I expect the main cables are duplex stainless steel. But these do not have much sping to them so having something inline between the cable and the frame to provide extra spring for each cable could reduce the chances that any cable goes slack or lets a float provide enough pull to make another cable go slack. Some inline-spring can also reduce the "load cycling" and "fatigue" of the main cable. Please discuss these options to provide some "sping" and any others you think might be better: 1) inline elastomeric mooring compensator 2) section of nylon rope 3) metal marine spring What diameter should the duplex stainless steel cables be? What specifications for the "spring" if any? Please try to optimize the design so the seastead can handle waves larger than the Caribbean sees outside of hurricanes. How high a wave do you think your design could handle? It seems the dangerous case is if a wave is hitting diagonally. If we were using a sea anchor and the biggest waves were just coming from upwind, so the seastead was always pointed into the waves, then we might be able to handle even larger waves? There are a number of reasons we want the "spring" at the end of the cable up by the body: 1) Easier to have cameras or sensors to monitor the stretch and so know how much the load on the cable is 2) Easier inspection and replacement access 3) Last longer if not in the sea water Note that the seastead will heave up and down with large waves, it does not stay totally still as a wave passes, and it has a very sizable gap between the water and the bottom of the living area so "pounding" on the bottom of the living area or "Under-deck Slamming" is not a issue I am worried about here. Just focus on the cable issues for now. Please discuss if we need to adjust cable tension over time and how we should do this if needed. Also discuss fatigue/inspection/cleaning/replacement issues. For each cable position we will want two attachment points at each end so we can attach a new cable before we remove the old cable. Please discuss the issues with moving tension from the old cable to the new one.