On Gran Canaria in the Canary Islands, there is good snorkeling off Puerto las Nieves especially to the lefthand side of the pier. The waters off Puerto las Nieves are known to have strong currents, so its really for experienced snorkelers. Try not to fight the currents, just drift with them near shore and then swim hard to get back in.
There are not many reefs or rocks here, so you can expect to only see parrotfish, lizardfish and wrasses. TIP: For your safety, most of the Canary Island snorkeling dive sites require snorkelers to have a diver-down flag marker. The waters around the islands are very popular with windsurfers and boaters, which has resulted in some snorkeler deaths over the past few years.
Overall, Puerto las Nieves is the 9th most popular snorkel dive spot of all 12 snorkeling dives in Canary Islands.