Go to SOLAR CAVE and bring a FRIEND (didn't join on the current mission) that is a water type or can float over water. At my last check you DO NOT NEED A KEY!!!!! After getting Dive and Waterfall (AND STILL HAVE THEM!!!)(I keep mine in K. Storage), there will only be link cables until you lose either one or both. L00K!!!!!!
GO TO WYVERN HILL AND THERE ARE HM'S!!! No Keys though :(