Two men untied the Ribco Seafarer 36 from Rose Bay Marina at 9pm on May 9
They towed it to a boat ramp, where it was loaded onto a trailer attached to a ute
The white Volkswagen Amarok was seen heading north on New South Head Road
The boat, which belongs to a charter company, is 11-metres-long with a black hull
'Police understand there are only a few of its kind in Australia,' NSW Police said