Transom drain plug in or out for towing?

[Bsmith]

What is the best practice: drain plug in or out before towing or short storage on a trailer? Use grease or anti-seize on the plug threads or not?

 

[Levitation]

Plug out is just daring Murphy to pay you a visit.
We saw a 27 Tug sink at the dock from dead batteries, a major rain storm, and being ignored.
We saw a 25 Tug almost sink when launched without the plug. It was realized when the boat pulled up to it's assigned slip, opened the hatch to get cushions and dock lines and realized it was filling with water. It was a scramble to motor back to the ramp and get onto the trailer before it became too heavy to be pulled up the ramp.
I don't like plug out when there is even the tiniest chance it could be launched that way.
I long ago made the vow that my plug will never be out, out of my sight. So far that has worked for me.

 

[Levitation]

Oh, and on greasing the plug threads. Just about anything is good. Marine grease or anti seize or wheel bearing grease.

 

[scross]

We pull the drain plug out when on the hard. It’s on our written checklist for both launching and retrieving. I also put a big sign in the helm window that says DRAIN PLUG when it’s on the trailer.
Just make sure you use a Bronze drain plug - not a Brass drain plug. Big difference.
We also use a touch of dielectric non-metallic grease on the plug.