I have taken a boat over a few times- 4-6m sizes-they are pretty regular cargo. Charged on total length vehicle/ trailer. One thing I would say is make sure your reversing is up to standard- apart from one time I have had to reverse trailer onto ferry- there’s usually a captive audience onboard…..😂- the staff are really helpful though and if you get a bit of performance anxiety someone will usually do it for you to save time..

Yup i had to back my beaat on - no pressure �£�£
Unless things have changed theres only one decent ramp and a not huge amount of parking.

Bit different if you're happy to beach launch.