Right on, lots of information there thanks fellas.
To be honest it is for 16 foot aluminum duck boat, so I am taking everything into account but i'm not running a whole lot of power at the end of the day (light bar and fog lights, led's under the gunnel on the inside, and as well on the outside, and a bilge) total amp draw for all of them running at once is 22 amps.
It'll be very rare for me to be using the bilge, so total amp draw of all the lights running is about 16 amps, i'll be running them off of a 32 amp hour Sealed Lead Acid battery. I live in Canada and it'll be fairly cold when I am utilizing it as a duck boat, so my battery will most likely be brought in and put on the charger after every use so its not outside in the cold and is always fully charged.
The longest time I would have absolutely all the lights going at the same time is about half an hour to 45 minutes max. Cabin lights will be used the most @ 2 amps, and someday i'll be adding a fish finder as well which doesn't draw much.
I will have inline fuses for the main battery run, the run to my headlights, a battery disconnect, and breakers at the switch panel for everything else. Everything will be grounded to a common busbar that will be isolated from the hull.
So at the end of the day I figure I'll do mostly crimp connectors, because they are easy and my wires will but tucked away into flexible conduit, so they won't be going through much abuse. My boat is also stored inside. I'll be soldering the connections to the LED's only, and sealing them with caps filled with RTV sealant for maximum waterproofing.