There are many good venues, but we recommend Les Basetes near Calpe and it may also be worth exploring further afield - Granadella and La Barraca (Jávea) are very scenic locations. You can rent snorkelling equipment from Les Basetes for around 10 Euros a day.

Take along some stale bread to feed the fish and you will soon be surrounded by a good variety of species. You may also see Octopus which are quite inquisitive.