I know, despite never dive with them, a couple of dive centers in east Algarve:
Bicho do Mar in Urb. Maria Teresa Lopes Vieigas, 11-A, Olhão. Phone +351 289 723 808 and Hidroespaço in Horta das Laranjeiras, Centro comercial Horta, Lote 1, Loja 2, Faro. Phone +351 289 862 500
I just eared about...