I am using this for winter sailing. I live in the northeast. What is the lowest temperature in which this product will keep me warm?
There is no specific temperature rating because every individual is different in their tollerance to cold. For Diving I have had women use 5mm in 67 degree water and some that use that in 75 degree water temps because they get cold easy. If you are not submerged then maybe your tollerance will be much greater, depending on how much water you will be exposed to. Its very subjective. In the heart of winter in the Northeast perhaps a 7mm will be good, Better to be too warm than too cold perhaps.