Not technically over the side, but off the transom. I lost my motor this past summer. I was doing Mach Jesus across the lake when all of a sudden, my arm yanked back. I looked behind me to see my 20hp Tohatsu doing death donuts on the surface for a few seconds before going under. I marked the spot well and went back the next day with scuba gear to try and recover. The water beneath the thermocline had so much sediment in it that it felt like someone closing me in a refrigerator when I went under it. Even with a flashlight, visibility was only 3-4". I had borrowed my dad's BC assuming it was in better shape than mine. I was wrong. When it was time to come up, I hit my inflator but never felt like I was rising and didn't hit the thermocline when I expected. Realizing something was up, I sunk to the bottom to try and get my bearings. I pushed off the bottom and kicked up while hitting the inflator until I saw light at the thermocline. I stopped kicking and started sinking again. I didn't realize until I was back boat side that one of the fill valves on my BC ruptured and was leaking air faster than it could fill. Went back again the next weekend with heavy duty magnets and grapple hooks but was never able to recover it. I like to tell myself that one day I'll catch the winning fish off that motor and it will all be worth it.
Besides that, I've just lost lures, scissors, pliers, etc.