Don't go overboard...the bag and the cookies ought to do it, in my opinion. Guys get funny if they think you over paid, or over thanked, them for what they'd probably have done for absolutely free each and every year. They might start to think that they owe you. Just a stray thought from a declutched mind.
Of course you know that, had you left the boat in until about Thanksgiving, tjk and T34C would have paid you to sail her over to the yard! Round about then they start thinking they pulled their boats too soon and that the likelihood of seeing another spring in their lifetimes is nil. Just a FYI. I use Thanksgiving as a target date myself; worst case scenario I don't make it that long, best case-it gets me out of talking with the in-laws! Some untrustworthy types hereabouts might try to tell you it is related to the fact that I rarely get my boat in much before Labor Day but, as I say, you have to be careful to whom you listen.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.