nah I don't buy it. it's just work Vs free time. Any serious sailor in their 50s looks shagged, and they've had all the outdoor space you can get. plus if you ask those people they'll actually be just 29.
The article talks about the benefits of living near and having access to green spaces, not doing manual work outside in the elements all day, which is clearly not the same thing.
It's not like sailors spend a lot of time in green spaces though. On serious note: exposure to extreme wind and sun day after day can't be good for your skin.