Couplers

A coupler, comprising:

• a first member having a first member bottom surface and a first member upper surface, said first member bottom surface including a first member coupling surface;
• a float attachment associated with said first member upper surface;
• a second member having a second member bottom surface and a second member upper surface, said second member bottom surface including a second member coupling surface;
• a weight attachment associated with said second member upper surface;
• at least one seal associated with one of said first member coupling surface and said second member coupling surface;
• wherein, when assembled, said first member coupling surface and said second member coupling surface both sealingly interface with said at least one seal;
• and
• a cavity within the interfaced first member, second member, and seal;
• said cavity bounded at least in part by at least a portion of said first member bottom surface, said second member bottom surface, and said seal when said first member and said second member are sealingly interfaced with said at least one seal.