It seems you are confusing 2 factors concerning our favorite enjoyment (DA beach / Hobies).
California: Yes, the water is cold, but it's the lifestyle of the environment a glaring example was Bay Watch in which a person entire being was surrounded by living and enjoying the beach in a 24 hour mode. Yes, you may sail in the day in Florida, but the environment is not present. I lived in Spring Hill for 3 years and enjoyed the beaches, but only one time it was truly a beachin lifestyle (spring break). Now take spring break and make it 6 months out of a year.
Jersey: We enjoy over 100 miles of coastline. The hot spots for the beachin and sailing lifestyle Point Pleasant, Seaside Heights, Long Beach and finally the namesake Surf City. We enjoy average water temps of about 60 degrees, and 100,000's of tourists a season, have you ever seen a boardwalk packed to the hilt at 2 am in the morning. If not come on up, and enjoy a beachin environment. Our season lasts from about May 1/Oct 1 in which you could literally party, surf, and sail in a 24 hour mode. Once again like spring break, but in monthly length.
My wife and I are of the beachin mindset; if the night is hot we will party, walk the beach/boardwalk, do a little bodyboarding and finally crash out in a hammock, only to do it again the next day. It was our intention many years ago to live at the beach. Now we do it, and whew it is a lifestyle. We are finally empty nesters and as the old expression said, "live fast but leave a good looking corpse".
Once again don't look at the forest, but the trees. It is the lifestyle, not only one factor.
