www.equipped.org/warning.htm Home brewed linethrowing guns and all of our other projects are fun to experiment with. Please remember that people read these posts and may be inspired to cobble together some Rube Goldberg copy and do personal harm. May I suggest another idea? Many of our emergency services lack funds for many tools. Perhaps a local effort to raise funds for, ie a dedicated linethrowing gun for the folks that might be called to a lake or river emergency would be in order.