Eric,
IMHO there is NO good reason to put a beach cat trailer in the water...none, nada, zilch. Even if you go through the proper steps and maintainence. I learned the hard way when I was a newbie back in the day (1975). I had a bearing seize on the 405 freeway in Los Angeles at 10:00 PM on the way to a regatta. Not fun. It was a brand new trailer that I put in the water to launch and retrieve. Never again and I haven't had any problems since (knock on wood) for a quarter of a million miles. Take good care of your equipment and it will take good care of you. Lesson learned.