Fire spells underwater
 

I would like to know whether all fire spells are outlawed underwater. Also, what about inherent abilities like Abysian heat and the like? Do they still have any effect?

Re: Fire spells underwater
 

Many are, but not all. (The divide seems to be somewhere along the lines of a fluffy understanding on whether the spell efect actually consist of producing flames or not.) Also, there are quite a few non-fire spells equally affected, including most, but not all, evocations. Your best bet to find out about particular spells is to check the manual. (It's one of the reasons I still have it sat on my desk after years of playing. And months of not playing for that matter. ;))

Re: Fire spells underwater
 

incinerate is about the only one that works underwater

Re: Fire spells underwater
 

Hydrophobia and Blindness also work.

Re: Fire spells underwater
 

Fire Shield works.

Re: Fire spells underwater
 

These spells work:
Blindness Fire 1 Alteration 6
Fire Resistance Fire 1 Alteration 1
Fire Fend Fire 2 Enchantment 5
Rage Fire 2 Thaumaturgy 3
Incinerate Fire 3 Alteration 5
Fate of Oedipus Fire 4 Evocation 4
Raging Hearts Fire 4 Thaumaturgy 5
Warriors of Muspelheim Fire 4 Enchantment 8
Second Sun Fire 8 Evocation 8

Source: http://wolfsbane.alwaysdata.net/Spells.html (Just a quick copy paste job, can't say if the results are accurate).

Re: Fire spells underwater
 

Either Banefire or Astral fire also works underwater- I forget which it is, but I believe it's Astral Fire.