Hi hardware gurus

Have a steel boat and metal 52 ac will be on a metal pole clamped to superstructure (rather than built in mast).

I have read the howto grounding linked from a newbie question about using them on a boat but am unclear how to access routerboard within case for mounting ground wire.

The howto suggested 7mm wire to base of mounting pole from routerboard so is there a point on the case or within it I should be using that accepts 7mm wire?

Or is this an auto ground due to the case being mounted to the pole? ie grounding for simpletons like me....

regards
Chris