The seamantle allows you to make a slam attack by forming a pseudopod of water, inflicting damage appropriate for your size. This slam attack has a reach of 30 feet. In addition, as a standard action, you can attempt to extinguish fires by touch.
The spell description only covers the damage dice for the Slam Attack it allows, but fails to state attack roll and static bonus damage. Does the Seamantle use your BAB+Str to make the attack roll? Or is it Caster Level + Int/Wis/Cha like many other spells simulating physical attacks? Do I add Str to damage? Or do I add Int/Wis/Cha to damage? Or do I add nothing to damage?
Do modifiers from Power Attack/Combat Expertise apply?
Since it doesn't state any exceptions, Seamantle grants you a normal slam attack with unusually long reach. You'd use all the normal rules for natural attacks, adding your strength mod to attack and damage rolls. You'd also be able to use power attack and CE.
That said, this is a great example of where following the given rules doesn't make much sense. A DM would probably be in right to houserule this spell to use a mental ability score for the pseudopod slam attacks.
Sounds fair. Anyone else wanna weigh in on this?
+1 on it being a physical slam if it doesn't tell you it otherwise.
I'm not sold on houseruling it though, a 30 foot range attack seems pretty useful.