I hoping to find the size or bulb number for the cockpit lights in a Powerquest 280. The bulb housings (2) are below the back bench seat. I'm assuming the bulbs look like this, but not sure because the all the cabin bulbs were missing when I bought the boat.

They are probably festoon bulbs and come various watts and led now. You will not want more than 10 watts and I would go with 5 watts.

I like the LED bulb idea. Does anyone have real world experience using LED’s in this application?

I've used them on 3 boats. Love them

Any links or part numbers for the LED variety?

Those lights come in a variety of lengths.

https://www.superbrightleds.com/sear...ducts/festoon/

Take a measurement and match it up with one of the LED replacements. I replaced all the ones in my boat with red but you can get clear or other colors.

The leds work great but don’t freak out if you put them in and they don’t work. You might have to swap the power and ground. Leds only let the power run one direction.

Yep. Just flip the bulb unless you have keyed sockets (example... 90 or 1156 housings typically used for interior spots, navigation, and some cockpit fixtures).