You might be able to use a large wooden curtain rod or the like for the harpoon, if you wanted it to be made of wood.
Cosplays for 2014-15:
[b]Simon Blackquill - Ace Attorney (85%)
Chief Prosecutor Edgeworth - Ace Attorney (90%)
Tsunami - Tenchi Muyo! (100%)
Luke Skywalker 2.0 (A New Hope) - Star Wars (20%)