My apologizes I used silicon in a vague description of what should be used 3M makes weatherstripping adhesive which is what I have used in the past
http://www.3m.com/product/information/OEM-Adhesive-Sealant.html
They also have marine grade stuff
http://www.3m.com/product/information/OEM-Adhesive-Sealant.html
They also have marine grade stuff