I am unclear as to Halacha of showing skin on beaches ( not wearing stockings or socks but wearing skirt) low neckline, show hair…when I am certain only non Jews are around.
Is halachos of tznius only in front of Jews or they are as applicable in front of Goyim?( this is a woman asking)
Your question is largely theoretical, because how can you know that no one there is Jewish? But let’s assume that you do have such an instance.
There are two main reasons for the obligation for woman to dress with tznius. The first one is for the woman’s own self respect and not to uncover herself in public, and secondly so she shouldn’t cause others to sin, whether it be physically or even by causing them improper thoughts. Both of these reasons apply to dress improperly in from of Goyim. It is inherently wrong for her to be undressed in front of other people, (as we see that the Gemora regarding her dressing improperly in public, daas moshe, that it doesn’t say that it is specifically when she in is front of Jewish men). Secondly the halachos of lifnei iver also apply to a woman not causing a gentile to sin. Therefore, essentially there is no real difference between goyim or Jews seeing her, and the halachos do apply even when it is only in front of goyim.
As a side point although women do not have the idea of watching their eyes to the degree that men do, however R’ M. Feinstein writes they also have to be careful not to do things that will cause them illicit thoughts, such as reading romantic novels etc. This idea can also come up when a woman is at the beach with other men.
Om Ani Choma -Tzion Hamitzuyenes 85, and siman 353, Minchas Yitzchok 7-75, Vayoshov Moshe 2-3, Shut Chasam Sofer CH:M 185. Igros Moshe E:H 1 69.