I'm pretty convinced these are moorings -- a concrete slab dropped to the bottom with a rope tied to a bouy on the surface. Note there are some with boats attached. They make no ripples, even with clearly visible waves and wakes in the area. (The ones to the east do seem to have some sort of effect on the surface waves, though.) The two moving boats don't seem highly concerned about avoiding them, making it unlikely they are at or near the surface.
Interesting theories. It never occurred to me that we could be seeing something below the surface. I guess the clincher will be if we can find a boat actually over the top of one of the structures.
See pictures on the pages linked to below. They show lot of boats docked in the same way boats docked at the rectangles in the images.
Also the boat with the wake is clearly weaving between floating objcts. It wouldn't make sense to weave between submerged objects.
Also, those are awefully large concrete slabs to hold a boat. The boats are relatively small and all the boats are smaller than the slabs. With an anchor that big you'd be docking huge boats and they'd have to be a lot further apart.
Also, there are clear grid patterns to the shapes of the rectangles when looked at close-up. Unlike what you'd expect of a concrete pad but more like what you'd expect of a cage or frame.
"The aquaculture Research Centre of the I.E.O. in Vigo has a staff of 5 scientists. Facilities include 20 tanks from 100 to 10,000 litres, phytoplankton and zooplankton facilities and all the related equipment for hatchery and ongrowing processes. Since 1982, the investigations have centred on turbot, black-spotted sea bream, sole, mullet, octopus and spider crab culture. The know-how of this technology is later transferred to interested industrial farms."
Anonymous
@ 2006-04-12 13:44:18
comon guys dont u know that you can zoom in in GE?
these are obviously some sort of farms on the surface (as kjfitz stated). you can even see that these floating objects are not solid but are rather a kind of grids/cages. also if u look closely u'd be able to see that there are boats floating by some of them
Anonymous
@ 2008-04-04 22:54:44
Mussel rafts. The mussels grow on large ropes hanging from the bottom of the rafts.
Sea - Misc, Info Requested 
Another check would be to see if there are 235 of them :) http://www.turgalicia.es/sit/ficha_datos.asp?ctre=nautico&crec=28411&cidi=I
See pictures on the pages linked to below. They show lot of boats docked in the same way boats docked at the rectangles in the images.
Also the boat with the wake is clearly weaving between floating objcts. It wouldn't make sense to weave between submerged objects.
Also, those are awefully large concrete slabs to hold a boat. The boats are relatively small and all the boats are smaller than the slabs. With an anchor that big you'd be docking huge boats and they'd have to be a lot further apart.
Also, there are clear grid patterns to the shapes of the rectangles when looked at close-up. Unlike what you'd expect of a concrete pad but more like what you'd expect of a cage or frame.
http://shellfish.cheju.ac.kr/invt98/seedprod-culturetype.htm
http://www.muckairn-mussels.com/
http://www.kames.co.uk/products/products.htm
http://www.tlpoe.com/Seed.htm
http://www.tgis.uvigo.es/ECOVIGO.htm
"The aquaculture Research Centre of the I.E.O. in Vigo has a staff of 5 scientists. Facilities include 20 tanks from 100 to 10,000 litres, phytoplankton and zooplankton facilities and all the related equipment for hatchery and ongrowing processes. Since 1982, the investigations have centred on turbot, black-spotted sea bream, sole, mullet, octopus and spider crab culture. The know-how of this technology is later transferred to interested industrial farms."
these are obviously some sort of farms on the surface (as kjfitz stated). you can even see that these floating objects are not solid but are rather a kind of grids/cages. also if u look closely u'd be able to see that there are boats floating by some of them