Boatmates Sailbuoy Stainless Steel Drink Holder with Koozie Reviews:
Works great on our J24 racer
Attached easily on lifelines (I use inexpensive cotter ring that 'locks' it to the line and ensures that it doesn't come off). Works great. It fits most cans and shorter bottles and even tall Nissan Stainless/Starbucks coffee mugs (could be a bit deeper for very tall bottles but works fine for most containers). Prevents spills when boat keels in strong winds.
I used similar drink holders on a previous boat years ago and they worked just fine. This one fell over board the first time I used it; it came right off the lifeline when I took my water bottle out because the hook is not sufficient to hold it on. Plus, only cans or bottles that fit in the koozie can be used because the holder is short and if containers don't fit in the koozie, they topple out. What a waste of money!