My dad was a massive fan of sea-going Napoleonic war stories in literature, and always said they would make amazing films (not to mention horrific- all that flying iron and splintered wood would be utter carnage). Its a shame this corner of storytelling never captured the imagination of movie goers. I really hope this gets off the ground.
I assume a prequel would be without Russell Crowe. So if it's the choice of another film but without him or no film at all... I would always choose the lesser of 2 weevils. I'll take the film without him... unless they can bookend it with Captain Flabjack having a flashback that'd work nicely for me, it's one of my favourite of Russell Crowe's roles