Its probably something you ate, than Lake Travis or your new wetsuit. I just got over a similar rash that stayed on my body for a good 3 weeks and it was from my neck all the way down to my ankles. The doc gave me some steroids for 5 days, which helped, but came back with a vengeance when I was off the medication. If it itches like crazy, pm me, I'll give you the name of this prescription strength cream that controls the itchiness.