A swim assist apparatus which comprises a fin member which is connected to a sandal by having forward connecting strap portions of the sandal engaging retaining recesses in the fin member. The fin member has a rear mounting portion positioned at an upper forward surface portion of a sole of the sandal and a forward fin portion which extends outwardly from the mounting portion. The retaining recesses have forward and rear surfaces which limit front to rear and motion of the fin member relative to the sole of the sandal to limit relative movement between the sandal and the fin member.