A male who goes to a beach where there are women dressed immodestly is oiver on many issurim.
If you go to a place where you are certain not to see anything improper, then there is no reason why not.
I don’t think there is any mekoir in Halachah for an issur histaklus for a woman. How can any woman go swimming if they will see others dressed in a manner that a man may not see? Does anyone have a source for this?