Also, look at:	Charterer (or the client) The person who reserves a boat for charter and his name is written on the charter agreement.			related sites
Sidenote Although it usually happens, there is no obligation that the charterer should be on the boat he/she booked.  A grandmother can very well book a boating holiday and offer it to her grandson as birthday present.  This doesn't mean that the granny should be onboard during the holiday, yet it is her name written on the charter agreement.