I'd check out
www.nada.com and look under Boats. There's a section for Boats,Outboard Motors and an estimated amount for the several type trailers. Just guessing, but if the Boat has Graphs, Trolling Motor and is as good a shape as you say, they should be asking for anywhere between $16,000 and $20,000. Blue Waves are very good boats and used Center Consoles in good condition are in demand. (I may be estimating too low.)
You also may want to contact Blue Wave, talk to one of their Sales persons and get an idea as to value.
Lastly, the TFF is a good place to list it for sale...Boat Section and the Trade/Swap/Sell Section.
Thanks!