68 deg water - no wetsuit

Maybe wear a tri suit rather than just shorts.  How long will you be in the water?  I think at 68 degrees you can tolerate it for a while until you really get moving.

Will be in the water ~ 15 to 16 minutes.  Don't have a tri-suit, just tri shorts. This is only my third tri - second this year.  Plan to do more next year but prob can't get a suit before Saturday.

Thanks for the reassurance guys...I thought I'd be ok, it's good to hear other opinions.

Thankfully  my wife did pick up a wetsuit for the tri we did in August.  She would freeze in the temps we'll be in this weekend...she loses heat like crazy.

The first Oly tri I did was without a wetsuit in 68F water.  I entered the water before the race to get the "junk" wet and take the chill out, and from there I was fine.  You'll warm up soon after you get going.

You'll love the wetsuit when you get it.

Did both races (1 sprint, 1 Oly) in 68 degree water this year, without a wet suit.  The first one I was able to do a practice swim two days before and found out about Diver's Reflex.  You can look it up on wikipedia, but basically, in cold water temps, the nose and face's receptors activate a mechanism for your body to slow the heart, vasoconstrict blood vessels, and conserve oxygen .  During the practice swim, my adrenaline got me out 100 yards no problem, but then I couldn't breath any more and had to lay on my back since I thought I would drown.  I couldn't figure it out since I am a pretty good swimmer.

When I got home, I looked up the symptoms and found out it was Divers reflex.  What I did on both race days, without any problems were to get in the water early and acclimate my whole body to the temps.  I also spent time just dipping my face in and blowing bubbles, all the while trying to relax through the divers reflex.  I used wax ear plugs as well (though, I never use them training) since I read that cold water in the ears can also make things worse.  Took a few practice "laps" and just concentrated on relaxing as the reflex went away. Anyways, that worked. 

But once you get past the shock and start swimming, you'll be warmed up and it won't matter any longer.  You will dominate on the T1 though, which is well worth it for a sprint.