Cold-weather swimming advice?

Question aimed at Ben, but for any more-experienced swimmers out there. I have a triathlon this coming Saturday, and the wildly fluctuating weather means that my in-pool practice has all been in 65+ weather. It’s currently 51F outside, and I’m about to put on a shorty wetsuit and do an open-water swim.

Any specific advice for cold-weather swimming? It’s 1/3 mile.

Thanks!

Ben is no longer associated with this forum. It was split off from his site in 2012 and is now run by Andrew (NewAgeServerAlarm).