I was raised in Los Angeles County on the beach. We typically wore beach attire and often went out in public in bikinis with shorts over the bottoms as typical summer wear. To this day one can see women shopping in the grocery or getting an oil change in this kind of dress in those places. I don't think the little skin shown in a pair of board shorts and a T will make the slightest impression in a beach community, let alone on the sand or in the water.
I am not advocating for nekkidness. I prefer people covered, I think God prefers people to be covered, and it certainly lowers the risk of skin cancer.
But I'd say if you are going to the beach, just don't sweat it.
When we go to the beach we just wear swimwear. Not the skimpiest string bikini but nothing that makes us stand out either, trusting that everyone's eyes are occupied elsewhere.
If you feel you must have special clothing for this rare event and don't mind spending a goodly amount of money for something you will hardly ever use there is great swimwear that covers everything. Check out sites that sell sun-protection clothing and swimwear for the best selections. You will even blend in at most beaches where there are now a lot of people that keep their skin covered for all kinds of reasons having nothing to do with holiness standards.