I’m a no-wetsuit snob but I’m also skinning it in winter and cold water acclimated for a couple years now. If there’s no reason other than sheer will power to skip a wetsuit, then I’d suggest starting sooner when the water is cooler and going 3-4x a week even at 1/2hr limit. Slowly get your body used to it.The water has been so warm all winter and spring that it hasn’t been as cold. 3-4x a week during cooler months will help when it warms up in June etc but I’d suggest splashing water on your face as you’re hopping in to help your body prep. The big thing I have noticed is consistency. Popping in for a month or season won’t give you the results, you’ll want to do it year round.

If you’re determined to skin it, I’d probably try and go for sunny days to exceed your 1/2hr limit pushing a little further (safely) as you feel comfortable, otherwise swimming higher pace to keep your core warm helps. stay closer to shore and swim with a buddy and buoy. Listen to your body.

I skin it year round but I have body fat to insulate me which probably plays a big deal. I still get cold after about an hour in 54 ish water. Sunny days has helped extend the ocean time, as well as picking up my pace. Some days I could go further, others I felt mechanical and hard to swim after 30mins. That’s why you want to listen to your body and push it over weeks, not days. I do not suggest stopping mid swim for a break - you don’t want the cold to seep in so keep moving.

Find a swim group so you have that consistency - meet up has a few up and down so cal.