Sooooooo last week I was fishing the Media Championship on Cedar Creek. Pull out bright and early and stop at Whataburger for a Breakfast Sandwich. While my partner was inside I decided to double check the fuel level in the boat. To check it I had to turn on the key. Uh Oh NO KEY!!!, Hmmmm Uh Oh NO Kill switch Cord!!!!! I always leave the kill switch cord connected and then I take the key and snap the attaching linksnap to the key and wrap it around the gear shift and snap it shut with a pulled tight loop. So I don't think It blew out. It appears some "Yahoo" decided to mess with me and took my key and cord that night at the Hotel. I guess they thought it would be funny since I have a wrap boat. LUCKILY I have a spare kill switch cord and extra key. Moral of the Story- Keep a spare kill switch cord and Key!!!! Academy has a multi kill switch connector cord for $9 and a spare key is cheap. Nothing worse than sitting on the boat ramp BLOCKING all the other folks while not being able to start the boat. OR worse yet, float launch it out and not be able to start it!
Some other things to consider to have as spares: Light Pole bulbs, or spare Light Poles, spare trolling motor prop & NUT & shaft pin, Jumper cables or Jump Box, electrical tape, pipe tape, super glue gel, tube silicone, auto tool kit, and I am sure there are other things that people can consider. Most are really small items that can make a good trip from a "BAD TRIP".

You are so correct in getting smart about "the little things" you take along on an outing. About 40 years ago, I started with a Rubbermaid "marine box" that is about the size of a shoe box. I still have it today, as it moves from one boat to the next I own. Each time I customize it for the new boat's needs. It is amazing how many "save a trip" items will fit into that box that is usually put away as an insurance policy. In mine, there's a spare kill switch lanyard as well. (They can break, so may be needed even without a prankster.)

Another item I added is a spare breaker for the TM. I watched for a good deal on eBay for a 30A Bussmann breaker so that having that spare wasn't very expensive. I probably haven't needed it because I have it, LOL.

Taking keys from competitors while asleep is a great idea.

I always removed my key from the boat. Think of THIS disaster: Some jerk/drunk/prankster walks by your well maintained boat in great mechanical shape....and decides to hit that starter a lick or two and run for the hills since the key is right there. Any outboard that starts dry like that will probably be fried before anyone could get to it to shut it down. What would THAT cost you? See why I never leave the key in it?

I have always carried a spare boat plug and a couple of fuses. It doesn't hurt to keep a spare "door" key for the truck hidden in the boat. I have used the spare key twice. I needed it three times.

^^^

I carry a spare kill switch along with a hidden key.

I just push the start button!!! And have extra kill switch cords

Hmmmmmm???? Where were you on the Night of Friday, October 27th???
Oh and a spare drain plug is needed too! Especially if you have the Triton Style that screws in!

What do you do when that "push button" fails , have an extra dash?

I've heard of this happening to someone... AT BASS PRO SHOP. Fried his motor. I personally have a battery cut off switch under my back lid. Shut it off every time I'm done fishing. No chance of yahoo walking by and starting boat if I leave key in. No messing with any electronics. Nothing stays on sucking battery life. No power pole let down, and I also have a cut off/breaker on my TM so no trolling motor coming on. Just the easiest way for ME to do it in my book. Battery cut of switch has so many positives.

I learned the trolling motor shaft pin the hard way a couple weeks ago

I usually keep a 9/16 socket for the tm prop. That's about it. The rest isn't needed. I am obsessive about PM and maintenance in general. If it's broke, it's immediately repaired. If it looks like it COULD fail, it's replaced.

Now in the truck? I'll keep more tools and a 30ft set of 2/0 cables for jump starting. But....I ain't overhauling a boat on the water.

very un-cool.

Did you have the cover on your boat?