Jimmy Riccitello, head referee for Ironman events, got back to me about cold water guidelines for Ironman events. Here is what he said:
USAT, our sanctioning body, does not have a cold water policy, like ITU does. They leave the decision up to each sanctioned event.
However, Ironman has a cold water policy that considers water temperature, air temperature, and whether the water is fresh or salt. Ironman has altered swims due to cold water and/or rough conditions and will always consider environmental conditions and the safety of its participants. If necessary, a decision to alter the swim will be made one hour prior to race start and will be clearly communicated to the athletes.
Bottom line, with regard to St. George, race operations feels confident, based on historical data, that the water will be “warm” enough for the full swim distance.
For those of you doing any cold water swim event, here are a few tips I give my athletes: