Some of stuff is more obvious than others and some items are quite unique.
Jumper Cables – Jumper cables have saved my day many a times as well as some other people I have run into. Its even saved a few tournament days. Sure you can always switch your cables over to the trolling batteries, but when you only have a minute or two to spare to get back for weigh-in, jumper cables save a ton of time.
Buoys - I know many a guys pass on buoys for GPS, but on windy days there is nothing like a buoy for a reference point, especially in these Boater/Non-Boater tournaments where co-anglers are not allowed to run the boat, so if you are trying to hold on a deep hard bottom spot in the wind, its nice just to be able to motor back to that spot and start fishing, instead of trying to feel your way around for it again and again. Basspro.com carries a great selection of buoys.
Extra Life Preserver – Its nice to have for those impromptu evening fishing trips with a buddy or coworker. You hate not to take someone because you only have one life jacket. Also, you can make someone’s day at the tournament take-off when they forgot theirs and you can lend them one.
Old-Fashioned Ice Fishing Depth Finders – This is for fish health! If you are not familiar with this item, it is basically a .5 – 1oz lead weight molded to a gator clip. I use these to clip on to the pectoral fin of a fish in my livewell that is starting to turn on its side. The basic premise, is that the fish does not have to fight and waste energy to stay upright and it recovers easier and you do not kill the fish and save on dead fish penalties at the scale.
Rope - Handy for tying up to docks, bridges&trees. Also good to have when you need a tow or try to tow another boat back to safety.
Small Anchor – An anchor can make life easy on a windy day and you have a real tight group of fish. Plus, I really like for sight fishing. Once you locate a nice fish, back just far enough away so you can see what you are doing and gently hold the boat with the anchor. Less trolling motor noise, more bites! It also can be safety tool if you lose motor power, you can sometimes anchor up instead of letting your boat blow into rocks or get pulled down stream.
Toilet Paper – When nature calls there is not always a restroom available and often boat ramp facilities are often out of this key supply. Enough said….
Cable Ties – I find these are handy for batteries that come loose out of trays, for re-securing transducers and many other things in the boat. Almost as handy as duct tape.
Multi-Tool– It’s a great single tool that can make those wiring repairs, loose screws and bolts. Rather than a toolbox, this tool can do most everything and take up a lot less room. You really cannot go wrong with a quality tool like the Leatherman Wave or Gerber 600 Fisherman.
Quality Side Cutters– Great way to remove really deep hooks from fish and can often save a fish that otherwise might go belly up in your livewell. Its also handy for cutting hooks that are buried into your hand or skin. Also can aid in cutting wires and other things your multi-tool may not tackle.
Hopefully you find these tips useful and makes your future fishing trips safer and more productive.