Almost everyone panic's at one time or another! Be happy that it happened. You now know that if it happens to you during a race that you can deal with it and get past it. Good for you! I freaked out at a 70.3 once when I lost my breath due to cold water temperture, but I recovered and finished the swim. Don't sweat it!
Where did you swim? I haven't done an open water swim yet and I have High Cliff coming up pretty quick! Not looking forward to that swim. I've been told it's a tough swim due to the shallowness of the lake, but I know it'll make me stronger mentally and physically.
Ditto! My first 70.3 was in 58 degree water with a wave start. I didn't warm up and freaked out when I hit the water. I took one deep breath in and couldn't exhale. I almost had to turn around and get out of the water. I was a Div. 1 swimmer in college and never thought I would be uncomfortable in water. Looking back, I'm sure it was the combination of cold water and nerves in my case. It was pretty scary at the time, but it turned out to be a great learning experience. I now get in the water for at least 5-10 minutes before every race just to adapt to the water temp.
I agree that it was good that you experienced this now but managed to finish the swim. Living in Florida, we swim in both lakes and the ocean. Swimming in the ocean is a whole different experience but the way to get used to it is to practice, practice, practice.
I've not experienced the panic in open water but my youngest son, a former Marine, did panic during his first open water swim while training for his first Ironman. It is a real thing. What we did was swim with him back and forth and finally the panic went away. My reward was that he smoked me on the swim in the Ironman race.
For those in the Milwaukee area, P3 started their Monday night swim in Pewaukee.
I also had the same experience as you did my first few tris. I took an open water swim class that was fantastic (trifaster - Lauren Jensen).
-Breath Every Stroke
-Know that you will be hit and loose your sighting at some point.
-The key out of the swim is to feel refreshed not winded, have a great pace to be ready to bike and run.
Practice, practice, practice. That is the only way you are going to get more comfortable in the open water. Are you planning on any smaller races before IMWI? If not, I would highly recommend finding on or two at the minimum. As much different as OWS is from pool swimming, OWS is totally different than OWS with a couple hundred of your closest friends.
As for the sun, I'd look into getting some tinted goggles - essentially sunglasses for swimming.
Almost exactly a year ago I panicked during my first ever triathlon here in Madison. I am a strong swimmer and swam in college but was not experienced at open water. During that event I swam to the paddlebords and hung on until I had the guts to swim to the next paddleboard. The oly distance swim took me 42 minutes. I successfully proceeded to get past the panic during the course of last summer. Yesterday I did the same event where I panicked and felt the same thing coming on at the beginning of the swim. I kept telling myself I have trained and am capable of this distance without question. Before I knew it I was rounding the last buoy and I left the water first in my age group and in 24 minutes.