Plan A would have been what you did - 2 hours over the side with a rubber dink clearing the prop from the rubber dink! As a kid I did that a few times - eventually the skipper
learned not to run over so much stuff (usually own mooring
).........and both of us are paranoid about anything getting tangled in the prop (if in doubt the engine goes into Neutral).....the prop will suck in a line.....doubt is cured by knowing where the line / rope
is - not simply from guessing (hoping) that it is ok......lots of peering overboard! / fishing
around with a boathook!
Swim Goggles or a facemask (sometimes you can simply untangle / unwind - if you can see WTF is going on)
Breadknife (for the serrated edge) - handle drilled for a line.
Hacksaw (it also cuts rope)
A line on the diver - plus the inflatable
dink hanging off the boat is also a comfort.
Never done one at night - but I guess a divers torch might be useful.
A wetsuit would be nice as well, get cold and tired fairly easiliy in temperate waters at least (especially fingers).
In your case, plan B would have been to set a 2nd anchor - out in the middle.......and to have remained on deck all night doing an anchor watch........and then have another crack at the shaft in the morning.
Plan C would be keeping the Inflatable
dink afloat - and with a grabbag to hand.