Harbor Dive is our dive shop of choice for everything, especially purchasing gear & equipment maintenance... We didn't find Harbor Dive until after we had already gotten advanced certification so the only class we've taken from them was for Nitrox certification-- the in-shop instruction was excellent... I might also add that this shop stocks a lot of great gear-- wetsuits, computers, regulators... I'm very concerned about diving safety and my husband and I both think these guys are the best!