How costly would a boat reception be. With a bbq and catering staff. Along with a stop where guests can get in the sea in a selected stop destination where's safe to do do.
I'd imagine very pricey. You'd need to hire boat crew as well as catering staff
Depends where your planning, I know the lakes have wedding reception cruises & or drinks cruises for weddings, check out the website for cumbria/lake district cruises..