Oh goodness Light! How scary!!! But I def. know the feeling. Last year at a sprint I did south of San Diego I was caught off guard. Same thing happened to me. It was very choppy, and I'm not used to ocean swimming. I used to SURF back in the day- but of course then I had a board to float on!
Ocean swimming is a whole other animal, and can be scary in bad conditions.
Like you I remember saying to myself, "CRIPES I can do an IRONMAN swim in a lake, but I can't do 500m in the ocean!"... And yes, I heard the lifeguard yell to his buddy "I'm going to stay with this one and make sure she makes it in ok"...

Glad you made it tho, and sounds like it was a fair race after you emptied your lungs of the sea water.
Good on you for keeping at it!