Currently, NREL investigated several designs, and has evolved what they believe is optimal. in Norway, a large floating project is supposed to begin construction next year (this year?). Italy tried to build a smaller test program several years ago, which to date hasn't gotten "afloat." The floating tripods pictured above may have come from a design developed in the Netherlands, at the turn of the century, which likely predated the principle power designs.
There's more under development under the radar, for sure. the rest of the world really doesn't have the giant pool table we affectionately call the North Sea.
I guess i'd have more respect for ocean offshore development in the US if they were already moving toward 15-20 Gigs/Yr on land, increasing annually, and with the concommitent investment on transmission. The Great Lakes? Hmmm, got an open mind there. "Life shrinks or expands in proportion to one's courage." - Anaïs Nin
In the picture, each of the turbines are oriented to face the other two legs of the tripod, but whether that is the design or it just happens to be illustrated with the wind coming in from that direction is not clear. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
"Life shrinks or expands in proportion to one's courage." - Anaïs Nin