really, as far as formal training goes, all he wants is someone (you) to absorb some of the cost as far as you learning. if he was fair he'd give you some training and then put you on a job that is suitable to your abilities and inform the client that you are new to longlining and come to an agreement on cost. for the amount of experience and proficiency gained in a few hours of training (which he doesn't want to pay for) it will not make that much difference to the client because you will likely not be able to do any precision longlining anyway.
there is some good advice offered in previous posts, however, as H70 says, "anyone who can hover can longline" is a gross over simplification. if i may say so and this is coming from someone who has >3K hrs of precision seismic longlining from alaska to mexico. not to toot my own horn of course
