I vote for you to do it RM! Heck, you're iron- a sprint will seem like nothing compared to what you did in April. The ocean can be a bit intimidating, but don't let it worry you. You used to surf, so you know you can be in the ocean and be fine. Get some practice swims in, and don't worry too much about it. You know you can go the distance, and I'm sure this will do wonders for getting you back on the tri wagon.
Go for it woman!!! Then, come back and tell us all about it!

p.s. are you back at home now?