Pokémon Mystery Dungeon: Blue Rescue Team and Red Rescue Team/Solar Cave

After beating Rayquaza and the credits roll you should have access to Solar Cave. Getting in will require the HM Dive, but Wishcash will give you one.

The Dungeon
From floors 2-14 you should find a key on floor 15 there’s a chamber with either a link cable dive or waterfall in it. On floor 20 which is the last floor you could find surf or a link cable.

Items

 * Keys
 * Moon Stones
 * Sun Stones
 * On B10F: HM Dive
 * On B15F: HM Waterfall
 * On B20F: HM Surf or a link cable