The solution was to trim the adapter that came with the unit down to fit the vent's opening. The Nicro Day/Night Plus Solar Vent has tabs on the inside, of the vent, for an insect screen. I trimmed the adapter down to size and notched out two notches for the tabs. After some tedious machining (trimming) using my Dremel, the adapter fit. I removed the adapter, connected the hose, place the adapter back on the vent, and checked if I could feel air being pulled out via the hose. SUCCESS!!
The last step was adding the peat moss. I added peat moss until the agitator could just barely touch it. Then I added water until the peat moss was a little moist.
Approximately, 6 months after starting this project it is complete!! YEAH!!!! (The only reason that we didn't complete this project earlier was we had more pressing projects, like getting the boat transported,etc.)