Pneumatic Spear

The pneumatic spear consists of two, compressed air-powered reciprocating saw blades mounted back–to-back on the end of a long pole. Its primary intended use was to easily cut breathing holes in thick ice. However, it also makes an effective weapon. Once fully pumped up with air at the surface, which takes a full minute, it will last for 12 + 1d6 rounds of combat before wearing down and becoming nothing more than an awkwardly balanced and dull (-2 penalty to hit) spear before it is recharged again. The combat rounds need not be consecutive and it can hold a charge of air indefinitely.