Bottom paint is a huge turnoff. Not that you should hide the fact that it has been kept in the water, but the majority of performance boats are not kept in the water. I'd have it pulled, and have the bottom paint removed and gelcoat restored. Have the gelcoat repair work done. No one wants to spend money on a boat they just bought.
Also, to be bluntly honest, the cabin looks dirty; if its supposed to be white vinyl. If its a darker tan/beige, then you need to point that out. You need brighter pictures, and you can't have too many pictures.
You also have a lot ALL CAPS in your ad, stating no warranty and no trailer. While the no trailer thing is logistical, you can be more friendly about it. You could offer assistance in fitting the boat for a trailer, and you could price out a Nextrail or something similar, and offer the trailer with the boat for an additional cost. As for the NO WARRANTY in all caps; it definitely would spook me into thinking "what's wrong with the boat that he wants nothing to do with it forever?" People want to buy from a friend, and have a friendly, pleasant transaction. They will steer clear of a deal with a boat-load of caveats. Boat sales are down, period. Now its coming into the off season. You may want to start advertising what you would sell it for in the spring, which is probably a cheaper price, since you might not sell it until then anyhow. Right now every used boat buyer knows he has time and season; and therefore his price on his side. Hopefully interest rates are going to become friendly here again soon as well.