Click on an image above to read the brochure!
Well, here's an idea of what's on offer in the way of boat trips from the south of Tenerife (north to come next time I go over).
Trips go from either Puerto Colon - Playa de las Americas or from the port at Los Cristianos. Most of them offer a free bus service that picks up from various, larger hotels around the resorts. They tend to go out looking for Wales and Dolphins. Wales are pretty much a certainty to spot; they are Pilot wales which look like big, fat dolphins. The dolphins aren't always a certainty but I'd say around 50% of trips spot them. Skippers keep in touch via radio so if one finds dolphins, he'll get on the radio and tell anyone in the area so they can sail in to see them too.
There's a huge choice of boats, especially if you want to stay out for most of the day - catamarans, sail boats, cruisers ... offering drinks, lunch, water-sports and a trip around various parts of the island so take your pick.
In adition to the trips above, there are regular ferry services from Los Cristianos that run to the nearby islands of La Gomera and La Palma.
There are a wide choice of fishing trips too, though I haven't been on one of those (ever) so I'm not the person to ask (yet) but I can say that deep-sea fishing and big-game fishing off the waters of the Canaries are some of the best in the world with several world records being held here.
The national ferry services between the islands are