Using basic woodwork skills (sawing, glueing and hand drill) build wooden boats to race on a river/pond
Wooden planks (60mmx10mm profile is ideal), dowel for masts, wood glue, paper or card for sails, pencils, colouring pens, hand saws, drill and clamps
Cut the planks into lengths of 30 cms, cut dowel into 20 cm lengths.
Distribute to the cubs, ask them to then design their boats to win a race. They should mark the wood where they wish to cut and where the hole for the mast will be. Cubs can shorten the piece of wood and use the cut off for superstructure on their boats.
Under supervision cubs can saw their wood and drill the hole for the mast, glueing any cabins etc on as required.
Cubs waiting to construct the boats can design their sails these will be mounted by holes top and bottom to the dowel or by sellotape.
Once completed the boats can be raced to see which is fastest. ASk the cubs about sails, rudders and keels and what these do for the boat?