No not required.  I'll give you 2 examples. 1. Lad learns to sail quite well then gets RYA qualified.  He then spends a summer teaching at Minorca or similar, does well and so is asked to do it again.  Next year they ask him to manage the facility, which he does.  Following year they ask him to manage new facility in Caribean, facility gets bigger and he earns more. 2. Lad learns to sail quite well, gets RYA qualified and teaches at Minorca or similar.  Following year does it again but at a facility in Caribean.  Meets rich american who like sailing so buys small criuser and lad crews for him at big events around Caribean for the summer.  The following year the rich american buys bigger boat and asks lad to look after it and deliver it to various regattas on eastern seaboard.  The following year american buys even bigger boat and lad looks after it, except he has it built in Europe so lad has to take delivery and sail trans Atlantic.  American now has 80 footer and lad has girlfriend and sister on board as cook and crew and spends most of his time sailing between regattas on either side of Atlantic.  When owner is not using boat the lad invites his parents for Caribean cruises.

Both are true stories.

Well a glib answer would be "be an attractive woman". They clearly are finding it easier at present to gain sponsorship than men. That is because both male and female consumers are more likely to identify with a woman than a man and the marketing people who control sponsorship budgets understand this.

But more seriously..... 

One traditional route has been as a sailmaker. Racing yachts which spend a fortune on new sails often like to have a sailmaker's representative onboard to help the trimmers.

Alternatively, many of the sailor retained by AC campaigns established their reputations in Olympic dinghy classes. But the number of people actually paid to race is tiny. There are a lot more who make some kind of living while moving between regattas by looking after race boats, managing the maintenance required and organising the crew and logistical requirements for the rich but busy owners. The people who do that are invariably the kind of people who good at making contacts and building networks.

Ever met her? I have. A charming young women, full of life and certainly attractive.

It is very difficult to go pro.  Its all about being the right person at the right time.

Learn a trade ie. be that person who people want to have on the boat when some thing breaks and needs URGENT fixing. To go pro its not enough to be only a good sailor, u gotta bringh that 4th dimension allong with you that makes people want to sail with you.  For alot of people its just being that really good guy/gal that people enjoy being around and sailing with. Its worth considering the 2 following ideas.

• learn about engines, u'll never be as knowledgable as a mechanic but u would be surprised how simple the most common problems are to fix if u know where to look.
• learn about wiring ie. the display units.  and be able to identify the reason... say the boat speed/wind speed is on the blip.(da problem is not always at the top of the rig)

glenn