I first used Odyssey batteries in my stand-up PWC in 2005, because flooded lead acid batteries kept failing on me.  I'm still using that same battery today (2012)!  I occasionally use a desulfating pulse charger on it to keep it in top condition, but that's a long life no matter how you slice it.  We got a second PWC which needed a new battery, so I didn't hesitate to get another PC625.  Yeah, they're expensive, but not as expensive as multiple flooded batteries + hassle.  I'm so happy with the PC625 that I might invest in bigger Odyssey batteries for my bigger boats when the time comes.