I went on this boat trip with my wife and it was a nice day out of the busy salvador. for the price we paid (40R each - there is some places that offer the same trip at the price of 80, so dont be tempted, go straight to the maritime terminal and buy it there) it a nice day where you can enjoy the boat ride and the lovely beach near salvador. there is 2 stops at islands. the first was great, clean warm water, great beach but many pushy vendors that keep trying to sell stuff, and it was annoying. the second stops was useless, they should have let us stay the whole day at the first island, because on the second the dock near a restaurant and just want that you eat there lunch. they even closed the restaurant erea that we can not go outside (we managed to sneek out :)). that lunch cost 25R which isnt included (also the drinks on the boat).
there were also a man on the boat that all day long tried to sell us DVD of the day... as i said too many pushy people.
conclusion - nice to do the trip without all the other things that they want you to buy. just if you have free day in Salvador.