Dogger Bank is a large sandbank in the North Sea, where depths range between 15 and 30 meters. Certain areas of this, fortunately, are in international waters, and as such have been proposed as locations for building artificial islands.
A while back on the forums there was discussion of a secondhand cargo ship which had 11,115 square meters of deck space, with the possiblity of quite a bit more available by converting the cargo holds. The price tag? $6.5 mil. It’s looking like we’ll be able to get a ship with 10,000 square meters of deck space for under $10 mil (yes, I’m aware that works out to $1000/meter^2; however it’s likely to be cheaper, and we can potentially triple the space by converting the cargo holds). If we could get a cheaper means than this, then we’ll use that instead.
So, why not combine the two ideas? A major problem I’ve heard about shipsteading is the need to burn fuel in order to stay stable. In shallow areas, we could use stabilizers that dig into the bank. Not sure about the storms or waves. The shallow’s are often major fishing grounds, so there’s a potential export business. Perhaps kelp can be farmed on the seafloor as well.