There aren’t many opportunities to wear thong swimsuits outside of the summer months. Swimming indoors is an obvious option, but the pool I frequent, unfortunately, does not permit thongs.
Do you wear thongs when swimming laps?
Yes, swim laps 
in my gym’s pool, Attendants (male & female) haven’t ever said anything even when I also used the sauna & spa. Can’t really because of sex discrimination laws - lots of females wearing thongs there from modest Brazilian cuts to almost nude dental floss gstrings. 
That’s awesome, @aquamantriton. I wish my gym had a similar policy.
Fortunately, the management started allowing thongs in the mixed gender, adults only spa area. That wasn’t always the case. A few years ago, they asked me to wear a more modest swimsuit after someone complained. I’m really glad they were open to reevaluating their position as time went on. It gives me hope that they might relax the pool policy in the future.
I’ve been swimming laps exclusively in Desmiit thongs since about a year before Covid. Recently added a suit from OrocoJuco to the mix as well, but it’s not holding up as well to the chlorine as the Desmiit. 3 different indoor pools and 2 different outdoor pools. I swim 4-5 days a week and am definitely considered a “regular” now. I chose the Desmiit as it’s definitely a thong, but from the front is very similar to a traditional brief. I didn’t try to be “that guy” and go for a g-string, bulge, push up, see thru, micro baggie, mesh, animal print, just kept it simple. The key is to just act normal. Don’t do anything differently when wearing your thong than you would if you had on briefs or even board shorts. I’ve only had one pool very politely ask if I could wear a suit with a bit more coverage on my next visit. I didn’t make a scene or get bent out of shape, just made a mental note that if I were to go there again to wear a brief.
Great to hear you’ve had so much success wearing thongs to swim laps, @Thonged4Life. 
Maybe you’ll inspire some of the other swimmers to give them a try.
I do, but in the ocean. Swim from buoy to buoy.
I lap swim in a thong every chance I get. 
I’ve found that people talk for like a week, but if you stay consistent and don’t showboat it becomes “normal”. Just get in, do your laps, and get out like you’re wearing trunks. Be kind and courteous to people too…say hello and smile. Chat if they bring up conversation. As mentioned above, keep it conservative. Don’t go for the strings or the bulge/torpedo suits. A traditional thong cut is as minimal as you should go without interjecting too much sexuality. It’s a fine line and there is a time and place for the skimpy stuff…just not at lap swim or public pools.
I do on occasion at the gym pool, but it really depends on how busy it is. I have only seen a few others do it, and there has never been an issue. I usually check to see how many lanes are open before I decide what to wear. There is no swimsuit policy other than you have to wear a swimsuit to use the pool and hot tub, which are co-ed.
I took up lap swimming this summer. The policy at my local pool says it’s up to the manager to determine what’s appropriate. There are no specifics on which swimsuit styles are allowed.
I started by modifying my Speedo briefs to look more cheeky. Nobody seemed to care or say anything. Eventually, I turned a Speedo brief into a more conservative looking thong with a thicker waistband and 1/3rd back coverage.
I think the Speedo logo legitimizes the suit. Like others have mentioned, I just act natural, and people don’t seem to mind. If you know how to sew, all you need to do is cut out the elastic in the leg openings, take a bit of fabric off the back, and hem the legs back up.
That’s a great idea. I’ve always wanted to do that with name brand garments, like a Nike swim brief. A name brand swim thong would lead to greater acceptance of the style for men.
I like the Desmiit swimsuits because, even though the brand is not well known, they print a small logo on the waistband in a tasteful location.
Thanks for sharing. I enjoy reading about these types of experiences.