We are working on a seastead design that will have a 40 by 16 foot living area above the water. There will be 4 foot diameter legs/floats/columns that are about 24 feet long going out from from the 4 corners of living area and down into the water at 45 degrees, with half of each column under water. The legs/floats/columns will probably be made from 1/4 inch thick duplex stainless steel on the sides and 1/2 inch thick on the dished ends. They will have some modest pressure like 10 psi inside. The bottoms of the floats will make a rectangle about 50 feet wide and 74 long. From the bottom of each leg there will be 2 cables going to the adjacent corners. The boyancy force is lifting up and the leg pushing against the platform leaves an outward force that the 2 cables pulling in counter, so the leg ends up staying in place. There will also be a cable making a rectangle between the bottoms of all the legs so we have some redundancy in case one cable breaks. The seastead is about 36,000 lbs I think but this is NOT a normal boat hull shape, it is more like a tiny oil platform as far as drag. We expect to use 4 low speed submersible mixers with 2.5 meter diameter propellers as thrusters, one on each leg/float. There will be lots of solar and battery. This should move at around 0.5 to 1 MPH plus any help from careful use of eddies and currents. 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.