The traditional Ironbridge paddle is a simple and crude thing. Cut the plyboard into a rectangle 16in (40cm) long x 7 1/2in (20cm) wide. Cut the broom handle to a length of 50in (130cm). Cut a 10in (25cm) slit in one end of the broom handle. Insert the plyboard into the broom handle, screwing and gluing in place. Use the broom handle offcut to make a handle to go on the top of the paddle. You may wish to paint a coat of bitumen paint on to the paddle blade and lower part of the paddle handle to waterproof the timber - don't paint the upper 2/3rds of the paddle, as in warm weather you may end up with sticky hands