There are actually a bunch of ok choices with dingy lights. None of
them that I have tried are great for several reasons. First, most just
die in a short time due to poor construction. Second, they tend to eat
batteries. And lastly, they don't stay on.

When you get up into dinghies with hard bottoms AND transoms you have a
better chace at making it work because a lot of the newer hard bottoms
have a place to mount a 12 volt battery - if you want to.

My way of doing it is a bit jimmied. I bought a water proof flashlight
(the type with the rubber jacket) and found one of those dingy
flashlights at a flee market that was broken. I took the red/green lens
off of it, slid the rubber cover off of the waterproof light and slid
the r/g lens over the front of the flashlight. When I slid the rubber
back over the top it was so tight that it was still waterproof. I made
the light 2 years ago and it still works. The rubber is looking a lot
like a dead rubber band now since it has been in the sun so long but
the light has not given out. It still eats batteries but my solution to
that was to buy some rechargeable batteries and use those until they
die without notice and then I have the regular batteries as back up. I
use those until I recharge and so far I think I have only gone through
2 sets of normal batteries in the 2 years.

The stern light was a bit more conventional. I bought a normal stern
light from walmart for about $12 or so. It is on a pole with a cheap
clamp but it works fine with a little care. My outboard probably has a
way to get voltage from it but I never tried to do it. I just buy
batteries as needed for that. A friend, though, made a light with a
translucent 35mm film container and a bunch of LED's The battery he
has seems to last forever. It is bright and knowing him it was cheap to
make.

As for your story, there was a dingy in Mag bay in about 1993 or so
that was run over by a Panga. The Panga was bow high at night with no
lights and the dingy had no lights. Both of the elderly people on board
were killed. It's no fun to know about those things but knowing has
made me use lights all the time - in FL you get a big ticket but
elsewhere you can get killed.