The lighter sockets are just a holdover for 12V, obviously from the car market. The only nice thing about them is some are fused internally. Otherwise they are big, bulky and not made all that well.

I have a two prong Perco connectors distributed all over my boat. They are polarized.

And yes, I have one convertor cord made up that goes from the perko connector to a lighter socket in case I need it.

When stuff comes on the boat that is staying on the boat, the connector gets changed.

Good idea for the USB connector... may put one near the nav station.