Know the value of your work. If they're only willing to give you 3% of what they paid for the previous one, then that's how much they (cynically) value your work. Without knowing how much they paid for the last one, It will cost them a hell of a lot more to commission a photographer to go out and take those photos...I'd be pretty certain of that!
They're a shipping company and will use and abuse you and spit you out the other end. There is no copyright law that would stop you selling a photo of the ship, nor that would stop you putting it in a photo library (RF or RM). Trademarks and patents are for different protections - i.e. against passing off, counterfeiting and direct copying of items. They have no rights over any 'royalties' as there are no royalties to be paid - the ship is a functional item, not an artwork. Functional items are not copyrightable items. Their name/logo is on it as a matter of function, not art. If it where otherwise, then Ford, GM, Boeing, United Airlines, BA, Virgin, Heinz etc would demand royalties for every single image of their products ever taken/printed/sold.
If you decide to play along with their game, get legal advice before signing or agreeing to anything to do with them or you will be worse off afterwards and will resent it because you'll know you've been stiffed.