Securing a Pedastal Seat to a wood deck

[wrfalpacas]

What is the best wat to secure my pedastal helm seats to the wood deck on my starcraft resto? I have a 1-3/8" thick wood deck in the reinforced seat locations and 9" Dia 6 bolt hole Pedastals. I was thinking 1-1/2" Stainless Lag screws with 5200 Marine Adhesive in the holes to seal them and waterproof the holes.