The round thing at the top that looks like a bowl is actually something that one person stands in and with the use of a paddle they navigate around the water. Fishing boats are docked off-shore and the people take one of these things to paddle out to where there boat is docked.
They are made of some kind of woven material like a basket and sealed. Some are black and it looks like the outside is sealed with a tar substance and some, like this one are much lighter. Across the street from the part of the beach where the fishing boats are docked you can see women weaving these floating baskets.
If you look carefully at the picture above you can see at least one of these near the center of the photo close to the furtherest fishing boat. It looks like it is paddling either to or away from one of the boats. If you look really closely I'm sure there are more of these around the boats. It mostly looks like a big dot next to the the bigger boats.