This pilot ejects because his plane’s brakes failed and ultimately caused the jet to plunge into the water.
This pilot ejects because his plane snapped the “stop-cable” which normally would prevent an aircraft from continuing on into the water.
This pilot ejects because…well, I don’t know why. But his plane drops something big and then it starts to pitch. If you know what’s happening here, please enlighten me.
I don’t know why exactly, but all three of these videos seem so comical to me even though there’s nothing funny about a pilot needing to eject from his plane. Still, the relatively slow manner in which these happen — meaning, not during combat or anything — makes the videos somewhat entertaining.

In that last video, the big thing he drops is most likely an auxiliary fuel tank. My understanding is that the A-Intruder lost one of it’s two engines on takeoff, and could not gain altitude. Also if you look close you see that two people actually eject, the pilot and the bombardier/navigator.