Personally, when we were selling our O'Day those different online ads did nothing. Unfortunately we ended up with a broker where their fee is 10%. We live 5 hrs from where the boat was stored for the winter and since it did not sell while in the water with the online ads a broker made sense as making multiple trips to the boat for a dead-end prospect did not make sense.
What helped the sale was I included a spreadsheet of all the improvements/maintenance of the boat...what,yr, why, cost, pro vs owner,etc. The new owner wanted me to take it off the market til they could get a professional survey which would take months. I played hardball and refused to sign. My documentation spoke for itself and the sale went thru.
Another thing....I HATE when people ad their boat with crap all over. Clean up the inside, unclutter your personal crap and let the new owners see the purity of the boat. Would u sell a house with dog toys spewn all over, lawn not cut, dirty dishes? Doubt it....
Good luck, I feel your pain of selling.