Another system for thru-deck mounting uses a pair of specially designed Mounting Flanges. Edson's bored 978-35-6D Deck Flange Mount for 3-1/2" Radar Masts allows the mast to pass straight through the deck of your boat, along with using Edson's 978-35-6B Base Flange Mount for 3-1/2" Radar Mast (sold separately) that has a shoulder to support the bottom of the mast will secure the Radar Mast in place. Edson suggests that large washers or backing plates be used when securing these Flanges to the deck or hull structures.
