From a natural justice perspective, essentially what you're doing by providing bail or security is substituting whatever that form of security is for the vessel. Perhaps the logical way of looking at it is that the most you're ever going to get is the value of the vessel, simply because, were you to proceed to prosecution and the court decided to forfeit the vessel, all you're going to get is from selling the vessel.
And frankly, I think that releasing the vessel in exchange for cash security or something like that is probably easier for the crown, because they won't have to go through the process of selling the vessel eventually.