Just a wild stab...but many smaller boats are wired in exactly this way:
(1) a larger-gage, say 4AWG or bigger, unfused red cable (should go to positive battery post) and (2) a same-sized unfused black (should go to neg post), these would be your cables to your starter/motor (and what the motor's alternator or rectifier uses to recharge the battery).
Then (3) a "medium," say 10-gage or so, red wire that should have a 30 or 40 amp or so fuse or breaker in it (goes to positive post) and (4) a similar-sized unfused black wire (to neg post); these feed the fuse (or breaker) panel that is probably somewhere in the cabin / cockpit..
Finally, (5) a "medium/small," say 14-gage brown (or possibly red) wire that also should have a 5 to 10 or so amp fuse in it (goes to positive post) that feeds the automatic float switch on your bilge pump.
When you say, "can't get it to electrify," do you mean it won't crank the motor, or that you have no power to things like lights/VHF, etc. (i.e., items fed by the fusepanel)? If the latter, then check the fuse that should be in "wire (3)" above. If the former, then that could be anything from a blown fuse or fusible link on your motor, to a fried starter...we'd need more info about what motor you have.
(If you've been touching wires to the wrong posts on the battery, good chance you've blown a fuse somewhere)
