My experience is that once a wetsuit gets wet, you are wet until you take it off. Without some wind resistant/proof covering over the wetsuit then you are wet AND cold. Since I find being dry much more comfortable than being wet, the wetsuit is my choice only for scuba diving. You should get a drysuit that is breathable because it is very much more comfortable than one that is not and significantly extends the confortable temperature range upwards which would be even more important in warmer areas. Yes, they are not cheap, but if you get one it is worth it because then you can comfortably sail during more of the year which makes it and your bigger investment (boat and sails) more usable and valuable. Also, it could easily save your life since it takes surprisingly little time in cool water to get hypothermic. The Coast Guard has a 50/50/50 rule of thumb that advises a 50/50 chance of surviving 50 degree water for more than 50 minutes.

Even relatively warm temps can be dangerous with enough exposure time - The Canadian Coast Guard rescued four people in Lake Erie for about six hours this summer with a water temp of 78 degrees and one was hospitalized for hypothermia. So that is how you can sell it to yourself as well as the spouse if that is an obstacle (You're worth it, right?!)