How long of triathlon?
How much swimming do you currently do?
A half mile swim is not a walk in the park unless you know you can swim it. Then add in all of the other participants and see how much harder it will become as they try to swim over you and pull your legs to get you out of their way. I ran an event called a Splash-N-Dash at my YMCA where we only swam 200 yards and then ran two miles. I can tell you that we had someone almost not finish the short 200 yard swim. I had a lady that has over 500 miles in our pool, almost have a panic attack, and switched to the breast stroke to calm down and finish her swim.
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2007 Jamis Ventura Comp
2006 Jamis Explorer 2.0
2000 Specialized Hardrock (bought used)
Swim, Bike, Run and sounds like fun