Is it a good idea to turn off the 3 ball valves for the ballast if leaving the boat in the water for a week? We don't have a boat lift so it stays at our dock all week untill we come up the next weekend.
Only thing I worry about is something coming off and water flooding the bilge.
I never shut mine off and haven't had a problem, my boat stays in 7 months out of the year.
I agree with Ian. I have left my boat in the water all summer and no issues. I go camping and leave her in the water for a week without any issues.
On the other side if it gives you piece of mind then do it. It will take 30 sec's to shut them off and turn them on. i have found that no matter what other people do if i worry about my boat at night i will not sleep so i will take the extra step just for my own piece of mind.
It's a very simple precaution and well worth the peace of mind. Pretty easy to reach too.