Many Brats put a piece of starboard on their transom so they can experiment with transducers etc. without constantly filling old holes and drilling new ones. I'm like that about electronics. Never totally satisfied, I like to experiment but after seeing and filling'/matching dozens of holes forward of the helm I decided to take a page from the transom guys.
I installed a removable starboard "shelf" just forward of the helm and it will be used to mount my "current" chart plotter/sonar/whatever else. 4 holes are used to screw up into the shelf "legs" and tapered to fit the location.
This is the shelf with legs

This is the mounting location, predrilled

This is the final installation. Not screwed in yet, I'll wait until my electronics are here. President Buchanan is holding it down temporarily.

If I decide to switch the stuff around or upgrade it's a lot easier to replace a piece of Starboard than fill/drill yet again and if I'm lucky I may not even have to replace the Starboard.
Don
I installed a removable starboard "shelf" just forward of the helm and it will be used to mount my "current" chart plotter/sonar/whatever else. 4 holes are used to screw up into the shelf "legs" and tapered to fit the location.
This is the shelf with legs

This is the mounting location, predrilled

This is the final installation. Not screwed in yet, I'll wait until my electronics are here. President Buchanan is holding it down temporarily.

If I decide to switch the stuff around or upgrade it's a lot easier to replace a piece of Starboard than fill/drill yet again and if I'm lucky I may not even have to replace the Starboard.
Don