Leaking Chainplates/Cooler Answers
First, the chainplates. You said "I beleive I have slight leaks at the location of chain plates on the deck." Even a slight leak is a bad thing. You should remove the chainplates completely, inspect the deck material and the bulkheads for rot and strength, replace the chainplates and rebed them.Don Casey, in his book "This Old Boat" said this should be done every year on older boats (20 years was the age he gave). I didn't believe that you had to go that far, that a visual inspection was enough. What I didn't realize was that small amounts of water were leaking down my chainplates, rotting the bulkheads, and the nice teak laminate was covering up the rot very nicely. The only way I would have known was to remove the chainplates and inspect the wood.Recently, one of the chainplates pulled loose. With no support on the starboard side, the mast came down. So, now instead of only having to pull the chainplates and rebed them, I have to replace the bulkhead. Don was right, I was wrong. Go figure.On your cooler. The reason it's not connected to the drain from your sink is that the drain on the cooler sits lower than the drain on the sink. You can probably put a "y" connector (a previous owner of my boat did), but keep in mind that when you heel over to the port side, the opening may be lower than the waterline. This will allow water into your cooler. It shouldn't be a problem, unless you have something there you don't want we with lake or salt water (opened food, stored dry items, etc).I make it a habit to keep the seacock closed on my boat, unless I'm tied at the slip. Then, I only open it to deliberately drain the water in the sink or cooler, then close it back. I prefer that to draining into the bilge.