All yachting salaries are determined by a wide variety of factors. As the saying goes, "you get what you pay for". One factor is the amount of time the yacht is used by owners and charter guests. Another issue is the planned itinerary of the vessel as well as any other above average responsibilities. If the vessel will be running with a short-handed crew (less than average) they should be paid more. Of course the individual's personal training and licenses as well as their practical experience should be compensated for if they are applicable. Sometimes an owner or captain may request "entry level" crew and a base salary should be expected. It is also quite common to be hired at a "starting wage" and have the opportunity for further negotiations once a trial period has passed.
There are many other benefits that should be considered when negotiating a salary. Most yachts will cover many personal expenses such as meals, uniforms and even shoes. Many yachts now also include a monthly phone allowance and paid vacations including airfare. The supply / demand curve also varies greatly depending on the position, the location of the vessel, how far along in the season and how many qualified crew are available at the time. You can always pay the going wage, but sometimes it may be wiser to pay the "staying" wage.