Visit La Palma, take a look at the crystal clear seas that surround the island and you'll understand immediately that the subtropical waters provide a unique playground for scuba divers. The waters on the west coast offer cliffs and drop-offs, lava arches, canyons, lava towers and caves, and visibility of up to 50 meters.
Regardless of your level, there's something for you. There are diving centres on both the east and west coast, though I've only tried those on the west, where the majority ate in the Puerto Naos area, leading south to La Palma's marine reserve. Many of the dives are shore dives, partly due to the underwater topography, but also because the best dive sites are very conveniently located!
From time to time the seas make diving difficult, but one of the lovely things about scuba diving in La Palma is that when the sea is choppy on the west, it's flat on the east, and vice-versa, so diving is more or less always possible.
The two most popular diving centres are in Los Llanos and Puerto Naos, but I believe there are others. However, some close off-season, so check before you book your tickets! Similarly, Nitrox is available at some centres, but always check first. The staff in the main dive centres usually speak English, Dutch, German and Spanish. PADI Scuba Diving Courses are also available, from PADI Open Water Diver (beginner) to Divemaster (pro-level).
The water temperature around La Palma varies from about 17°-18°C (63°F) in February to a pleasant 24°C (75°F) in August, so it's never uncomfortable.
For information about the local diving centres or on PADI courses, see the links below.