WTF?

start at the back of your wave, relax and knock it out.  You will be fine.  Don't think about not being able, just think about rounding the buoy and take it from there.  No worries.

Glad to hear it!  It must be a confidence booster to have the breakthrough and know that you can go the distance!

I've found that fitness gains come in spurts.  For long periods of time I'll feel like I'm stagnant, and then all of a sudden my fitness gains will catch up all at once.  Sounds like you had your breakthrough at a perfect time!

My two pieces of advice that got me thru my first (and to-date only) OWS in a tri.  First, don't focus on the entire distance.  Think of it in terms of segments.  It was a triangle course for me, so it was easy to just keep thinking about the buoy up-ahead and the fact that it wasn't really that far away and getting closer every time I looked up.

Second, and perhaps more importantly, keep putting one arm in front of the other.  I slowed my pace down, barely kicked at times, and generally tried to keep my heart rate and breathing under control (my form was horrible).  But I always kept putting one arm in front of another.  I know people say switch out strokes or doggie paddle for a while.  But at a clinic I went to prior to the race, the instructor said never stop, because getting started again sucks.  So I never stopped with the basic crawl stroke.  One stroke after another.  I just kept thinking that the entire race.  I ran out of the water 1:20 faster than my previous 800m best in a pool because of that advice.

Oh, and third, don't bother with fancy breathing.  OWS is not the place to work on bi-lateral breathing or some other new technique.  Stick to the basics. 

HTFU!

BTW, I've run over 20 marathons, and not once did I ever do a training run that exceeded 26 miles.  Relax, you'll do fine!

P.S. My first tri was over 10 years ago, and I did every stroke known to man during the swim phase of the race.

rb