A general cut-off at 20m for small private yachts has been established for quite some time, and is on the whole respected. We see no call or reason to change that.
However, in a small number of cases such yachts are converted from commercial vessels, which in that form are covered by the site - eg fishing or military vessels less than 20m. We think that it is illogical that an 18.5m retired fishing vessel would continue to be eligible if abandoned (Wreck & Relic) or scrapped, but not if converted to a motor yacht. Here is a current example (a former Tasmanian fishing vessel):http://www.shipspotting.com/gallery/photo.php?lid=2884187https://www.trawlertraveller.com/
The Admin group have agreed to accept such vessels in the "motor yachts" sub-category and the Passenger Vessels FAQ has been amended accordingly:"Vessels must have a minimum LOA of 20 metres/65 feet, any pictures of yachts under this length will not be accepted. The only exceptions will be motor yachts converted from other ship types which have originally qualified in their category."http://www.shipspotting.com/support/faq.php?category=Passenger%20Vessels