I've spent summers for the last 11 years working on deep sea charter fishing boats, and for two of them, I carried a spartan. I found several of the tools were useful for fishing.
The large blade- pretty self explanatory- good for the heavier cutting chores. I've used it to cut through 1.5 inch three strand nylon anchor line and it stayed sharp afterwards, gut dogfish for the entertainment of intoxicated patrons, and to cut the cheeks and tongues from smaller codfish.
The small blade- useful for trimming the tag ends of knots in monofilament fishing line. We used 50 lb test, and spliced them with blood knots. We used overhand loops for the sinker loops, and blood loops for the hooks. For bluefishing we used the clinch knot to a swivel on a six inch wire leader. All of these knots with the exception of the blood loop have a tag end that should be nipped close. The small blade against your fingernail works well in a pinch
The screwdriver/can opener- The small screwdriver tip perfectly fits screws for the Penn 55, 60, 65, 113 Senator, and 113 HS reels. Great when a lot of the reels are 30 + years old and the screws loosen on a daily basis
The corkscrew- Superb as a backlash pick when the tourists open the bail on the reel without keeping their thumb on the spool and tangle it up. (aka a birds nest, a rats nest, etc...) The corkscrew gets the loops loose enough to work it free.
The toothpick- 1/2 of the toothpick is roughly equal to 1 nautical mile on a 1:40000 chart, or 10 microseconds of loran on the 13 bearing. Useful for a rough judge of distance
The tweezers- Picking the spines of redfish and cunner out of your fingers at the end of the day
The reamer- good for cleaning the threads of the reel mount on the rod of gunk, and punching holes in bleach containers to use as a makeshift sprayer.
The large screwdriver/bottle opener- The large screwdriver is good for countless chores around a boat, and the bottle opener is mostly used at the end of the day to open ice cold beers.
