25 years (or so) ago I was patrolling Lake Havasu, around Black Meadow. The boat was a 24' SKV Coast Goard boat, 454 V-Drive.
We had stopped a boat for bow riding, We were idling alongside while I was up toward the front writing out a "Notice of Violation" (the CG version of a ticket), while the crew was checking equipment.
I happen to look down toward the cabin, and notice there was water where it shouldn't have been. Yep! The Coast Guard Boat was Sinking!
I flipped on the bilge pump, heard it running, but no water was coming out the hull fitting. (Hose had come off)
Yanked the engine cover and found that the belt for the cooling pump had broke and the uncooled exhaust had burned through the rubber hoses to the through-hull exhaust fitting. Water was pouring in the fittings.
I stuffed a handful of rags into the holes, which slowed it down, but by then we were really low in the water. The engine had already stalled from the vibration dampner throwing water all over the place, and it wouldn't start up cause the starter was under water.
I asked the guy I stopped if he wanted to get out of the ticket, and tow us to the Landing, about 2 miles away. He readilly agreed and we gave him the line, while my crew was bailing with anything the could get their hands on.
About half way to the ramp a CG Auxiliary boat showed up. (I had radioed our problem, and had people on the way to Black Meadow with the trailer.) He tossed us an emergency bilge pump he'd rigged, and after about 10 minutes we had caught up with the flooding and were pretty much out of sinking danger. Was towed to the ramp and trailered without any more problems.
Closest I've come to sinking.
Now. How about a cheap and easy tip for that emergency bilge pump.
Buy a regular bilge pump, the more GPH the better. Wire about 20' of wire to it with clips on the end. Clamp about 10 feet of hose to the discharge of the pump. Then put it all in a pillow case or other container, and stow it under the seat, or wherever.
If you, or another boat is taking on water just drop the pump in the bilge, hook the clips to the battery (yours or theirs) and sling the hose over the side.
For about 20 bucks, you'll have a cheap insurance policy and the forever gratitude of anyone near you that's taking on water.