Newbie strategy question, Atlantis shore-bound...

[Valandil]

My personal favorite is acid rain. Fairly low fatigue, easy to boost with bracelet, and armor corrosion. Also I like the uniqueness of acid spells. Fire/frost is just too common.

[Taqwus]

Might also be a good time to consider mercenaries -- while there aren't that many amphibious mercenary groups (Shipwreckers come to mind... and they're pretty nasty), hiring one upon landfall would be a quick boost.