Sorry to chip in on my first visit to this forum, but I have to to say that WJM is coming over as Mr Smug!
I have no experience of the boat building business, but run my own firm of cabinetmakers. Every small (and large) business I know of in my field relies totally on deposits and stage payments for it's very survival, particularly in the early years when all profits are being re-invested in equipment and tooling, leaving little in the way of working capital.
There is no way that I could supply a new kitchen, for example, without taking a 25% deposit, a 25% payment upon commencement of the work, and the balance on completion. Yes, I am financing my business with my customers' money, but this enables me to provide quality work and a quality service. This is standard practice in most industries where bespoke work is being carried out for members of the public.
In the case of companies providing bespoke goods and services to other companies, the arrangements may be different because of long-standing relationships and ongoing contracts. Bank finance is far more readily available here than for firms doing one-off jobs for Joe Public. If I want to borrow from the bank I've got to put my house up as security. No way Jose!!
Too many members of the public go for the cheapest price and then wonder why they have problems with their supplier. I see this all the time with builders. A cheap builder won't get the job done properly because he's not making enough money! Most firms who go who bust, go bust because they don't charge enough!
Caveat Emptor is the rule of thumb when looking to commission any work. Do the research.
I was thinking of having a go at narrowboat fitting. Having read a few of the posts in this thread I don't think I'll bother!
Cheers
Brad