An inflatable doll can be a wonderful thing to have anytime your children are going to be near water. Using liquid latex or vinyl you can easily make one yourself in a very short time. Make dolls in the shape of people, fish, sea creatures or anything you can think of. The only limitation is that you must be able to draw a two-dimensional outline of it. You'd be surprised what you can create with a little brainstorming.
Draw the outline of your doll on a pane of glass with a permanent marker. Draw a 1/2-inch rectangle trailing off from one of the feet (this will be the inflation tube).
Draw a dotted line 1/8 inch inside of the edge line.
Apply 10 layers of liquid latex or liquid vinyl inside of the solid line, allowing each layer to dry before adding the next. Dab the latex or vinyl on, using a fresh sponge for each layer. The time required for the latex to dry depends on its thickness, but generally if you speed it up with a hairdryer it will only take a minute or two per layer.
Cut the shape of the dotted line pattern out of waxed paper. Lay it down onto the dry latex, staying inside of the dotted lines.
Apply another 10 coats of latex or vinyl. It will stick to the 1/8 inch of exposed material around the edges, creating a balloon, but will not stick where there is waxed paper. Dry these layers the same way you did the first ten.
Powder the doll with baby powder, then carefully peel it up, powdering the underside as you do.
Cut the end of the inflation tube open if needed.
Blow into the tube to inflate the doll.
Seal the tube closed at the edge of the leg with super glue.
Trim off the rest of the tube and any excess material from the seam.
Paint the doll with latex or vinyl-based paints.