Have you read the notes about leaks on my website?
Go here:
http://h260.com/leaks/H260_leaks.html
A leaking ballast tank is a very rare event. The ballast tank for the H23.5/26/260 is created by gluing the cabin floor to the hull with 3M 5200. One theory is that when the boat experiences a hard landing or is run aground this breaks that bond or seal.
One owner confirmed the tank was leaking by pulling the boat, making sure the boat and tank were completely dry, and then refilling the tank with a hose. There are no written repair procedures available; the repair process is different depending on where the tank is leaking.
If you would like to speak with someone on this contact Eddie Breeden at Hunter, 800-771-5556 x 3632. that said, unless you actually have a problem, my suggestion is don't bother Eddie with this issue.
Depending on the extent of the damage, it is possible that the value of the boat would make repair uneconomical. Insurance companies are more inclined to look at this differently than the boat owner.