Answer by  
                                                                                          erias71 (7)
                                                            
                          
                          
                                                          NADA puts out marine appraisal guides.  Another good option that your friend can try is to use BoatTrader, who puts out a magazine so that your friend can look up comparable models.  The last thing that I would suggest is for your friend to take it to a popular marina in their area and look for someone with experience selling.