59F at 90ft?
That’s warm!
Really comfortable, actually. It's not just a question of being used to it, it's just a question of dressing correctly. I think that a lot of warm water divers, even very experienced ones, just completely write off the idea of local diving when they hear the water temperatures.
If I told the average non-skier that I was going skiing, I kind of doubt I would get an immediate incredulous response or a good-natured claim that I was "crazy". If i went for a hike on a brisk fall day, no one would say "I only go hiking in the summer".
If you do outdoor activities, you dress for them appropriately! I mean, being cold is obviously subjective, and if someone says that they are uncomfortable, they are uncomfortable. Also, I know that plenty of people dive 7 mm wetsuits here and feel ok. But I think that if you take the average warm water diver and put them in a dry suit, they are a lot more likely to be comfortable and get into it.
I have been to Newfoundland. I know that there is a big difference between 34F and 60F, even though both are considered cold water diving.
I always encourage people to give diving in these conditions a good chance before writing it off. You don't ski in a bikini, and you don't dive in this area wearing a 5 mm wetsuit!