My children saw a nice artistic drawing of a Chasidisher Rebbe dancing while crossing back and fort some water pond representing the Yam Suf, while his many Chassidim were singing around him. They want to do the same in our basement this Shabbos Shirah. Placing a plastic sheet with some water and dance in it. Is it permitted?

There is indeed a minhag to do as you describe by some Chassidic groups during the last day of Pesach. However, on question 1736 we mentioned; “Many Poskim in our days prohibit not only swimming but just soaking even in an unheated pool. (Igrois Moshe E.H 2: 13, Minchas Yitzchok 5: 32, Beer Moshe 3: 56, Shemiras Shabbos Kehilchasah 14:12; Yaskil Avdi 6:1, et. al.) Different reasons are mentioned for this prohibition such as; One may improvise or fix swimming or floating paraphernalia. (Kitzur ibid.). Or one come to squeeze out water from a towel, wet bathing suit or hair. Even taking a cold shower is not allowed. Playing by a pool causes great loss to the intended holiness of Shabbos. However, when the immersion is done for a mitzva purpose, such as Tevila in a mikva, it is allowed. Poskim also permit when the bathing is needed for the ill (Yeshuos Moshe 3: 35, Piskei Teshuvos 339: n. 4).” One may argue that if one only steps in a small and very shallow puddle of water, similar to what one usually steps inside when walking in the street on a rainy day, and is careful not to get soaked and then squeeze out the water, it should then be permitted for children in a basement under supervision. Horav Avrohom Kahn Shlit’a suggested the kids should wear boots or galoshes. Horav Shlomo Miller’s Shlit’a opinion is that one should maintain his family traditions.