Most of the Baltic Sea seams to be open, but that’s mostly near the coast. There are still huge ice covered areas, moved around by the wind. One day a coastal area may be open, the next day completely covered with ice floes.
Since the last nights were quite cold the ice floes partly froze together giving the illusion, that the sea would be covered with a layer of solid ice but no, the new ice between the floes is young and weak and wouldn’t bare you. I myself broke through this morning when taking pictures but directly at the coast, were the water is very shallow and I landed in only 20 cm deep water. No problem with rubber boots but I wouldn’t have dared it without good knowledge of this part of the coast.