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.






Assume for now that the cables are 3/4 inch diameter dupelx stainless steel.
Please try to estimate any noise or vibration that might come from the cables moving through the
water at:

0.5 MPH
1 MPH
1.5 MPH


If noise and/or vibration from the cables moving through the water is an issue which
of these would you recommend:
  1) Helical strakes
  2) Wing shaped fairing - snap on plastic, we are always moving the same direction so it does not need to rotate
  3) Some other solution?