2 inch dock pipe cap

My friend's boat dock was missing a cap on one of the dock support pipes, so I offered to make one. The first cap was simple and fit well, but seemed rather mundane. The second cap has a recess for attaching a solar light.

A quick internet search yielded the pipe dimensions. The resulting fit is good - snug but easy to install and remove. The gaps between the cap and the pipe are to make fitting easier and to prevent vacuum or pressure since the other end of the pipe is in the water.

If he