In need of a 2nd opinion, on avoiding an aoo while swimming.

[GM Chyro]

Hello fellow GMs.

Situation:
PC has managed to stay treading and keep his head above water, but is facing a crocodile in melee.

He at 1st wanted to do a 5ft swim away, to which i've pointed he couldn't, as he didn't have a swim speed.
Normally we use acrobatics to avoid an AoO, but he's got no footing here.

I figure he'll have to make a swim roll vs the croc's CMD, instead of the acrobatics.

Would this be an appropriate course of action, or does acrobatics come into play somewhere after all?

[brock, no the other one...]

This is one that I would have to dig into the rules to answer correctly. Since there usually isn't time for that at the table, a roll against CMD is exactly the right way to handle it to keep the game moving. If nothing else, it rewards the player for not dumping their (seldom used) swim score.

[SCPRedMage]

Personally, my interpretation is that:

1. The Swim skill rules don't cover this.
2. Acrobatics can't be used this way if your speed is reduced, so no using that if you don't have a swim speed.
3. Obviously, no 5 foot step,
4. Withdraw action would work.

[LoPan666]

The rules for Acrobatics disallow using it to avoid an attack of opportunity for moving through a threatened square if your movement is reduced due to medium or heavy armor or encumbrance - it does not disallow such use if your movement is reduced for other reasons. I would still use the standard Acrobatics rules while swimming.