Here is another photo from Flathead Lake last weekend. This is a Hobie 16 just like the one I have. (Mine has blue hulls however and this one is yellow.) But the sails are exactly the same colors. You can date a Hobie "cat" 16 by the colors of the sails. These sails are from the late 70s. But I suspect the boat is newer like mine or it is well taken care of. My boat is an '81. There are more and more Hobie 16s on the bay. This is the only one that I have seen with the same sails as mine and it just showed up on the bay. So if we go out at the same time it will be hard for people on shore to know which one is me. The bay is so big that you can't see the numbers from any distance. I did notice even from this distance that these sails are in much better condition. Mine are really bad but still working. The people I bought my boat from left them out all the time. I'm going to use them until they totally fail. I've had some work done on the main at the tack, and also bought all new batten ends.
The number on the sail represents the number that exsisted when that boat was produced. The problem is that people buy second hand sails and put them on newer boats, or they buy new sails and put them on old boats. But the number only really matters when you race not the colors. Plus you can order old colors if you want. It just costs more. Every year they offer standard colors for that year in various combinations, or you can just get white. Here is a link to the Hobie website. They have lots of cool things but to see the catamarans you need to click on the sailing tab.