Swim platform installation ?

[abl1111]

I will be installing a full-transom, teak swim platform on my 23'Tsunami w/ an I/O ( possible fishing obstacle, but it will allow the wife to get on and off when we 'beach it' ).

It's roughly 21"-22" wide by 6.5'- 7' long. I will be using (4) AFI S.S. brackets - these are solid, triangle shaped.

How high above the water line should I mount this ? Is there a try-true method I should know about before I start drilling holes in my beautiful, new transom ?

I was thinking of oversize drilling the holes and then re-filling w/ epoxy and re-drilling to avoid any water intrusion.

Any input ?

Thx,

Alan