I'm glad you liked it.
I'm considering getting a second level of fighter and going 17/2/1 since the loss of level 18 cleric is minimal at the current time. Plus, as you mention, more strength and an extra feat. I am probably going to drop the THF line because I really should have both Skill Focus and Athletic for this build.
Shortly after first making this character (who is, sadly, still only level 4--my poor neglected Swimclerik!), I was running Redwillow's Ruins on another character and received the Plate Armor of the Deep. Definitely seems like one of the more useless armors in the game (+13 Swim!...and a -10 to Swim from the armor check penalty) but there was no way I could NOT equip it for the time being.
And you have hit on another good reason for Charisma! Ladies, watch out for Swimclerik! He's still a youngin but he's already making waves!
The Aquaman build may be the best swim build, but it surely isn't the best swimcleric build!
The Swimcleric would be a good ally to the Doorstop Paladin, as the Doorstop Paladin is not suited to the ways of the water with his low strength, heavy armor, and tower shield.
I smell a lawsuit!