This may be true but IMHO it's a horrible business model. An approach I will often use is to give a realistic "hip shoot" or "ball park" and then explain that I am six months or 8 months out before I can get to the work.. FWIW it is impossible to give "accurate not to exceed quotes" for marine work unless you screw-over most customers, like car dealers do using the flat rate system. I've had customers still bite at that and then turn into tremendous customers, whom I did not piss off with my original hip-shoot..Sounds like the Marina doesn't really need the work.
Greg
One such customers started with a 27 footer, he then proceeded to get a new boat every two years, he just closed on a $450k boat two weeks ago.. Yep, I have done all the work and refits to all of his boats and he waited 5 months for me to start on his 27 footer. I just quoted over 42K in work to his new boat. You never know which customer will become one of your best so why risk pissing them off.. Just be honest....