Pokémon Mystery Dungeon: Blue Rescue Team Tips

Beating the game will unlock Solar Cave after you talk to Lombre in Pokemon Square. The cave is not that long (20 floors), but pack supplies just in case. When you get to Floor 10, you will find a key hole somewhere. I found a key at the end of the dungeon. There is also a key hole at the end. Use the key there and you should get the HM Waterfall. After that, the keys will no longer be there. It will be in a desert-like dungeon. There are key spots in other places but this; Western Cave and Wyvern Hill, for example.

Dive: Whiscash after main story is beated AND Solar Cave floor 10
(Key required) Surrounded by water, bring a Water or Flying pokemon
Waterfall: Solar Cave, floor 15 (or possibly 10). Key required, surrounded by water.
Surf: Solar Cave, floor 20. Key required, surrounded by water
Fly: Wyvern Hill, floor 30. Key required.

Moderator's Note: Merged two cheats together.