Sorry for the delay in commenting on this.
http://dolphinseafaris.com/ have now mutated into a group operating under the name of Seafaris.
See: http://www.seafaris.net
What they do not yet advertise on the web, but what they are punting at Lagos Marina this summer is their Lagos - Alvor - Portimão Marina water taxi service.
According to their current flyer, Lagos/Alvor - one way is € 10.00 - Return € 15.00 (per person, I presume.) Lagos/Portimão add € 5.00 each way.
Their contact phone numbers for Lagos are (+351) 912009075 and (+351 282 798 727)
