Calico Jack & Notoriety

[Pirate Petee]

It was a dutch ship I forget the name.

[Rumba Rue]

That is indeed a bucket boot. Here's the rest of the picture, that guy's got the matching boot and his pal's got a pair on as well.

One has to really wonder about the spurs on the boots. Clearly the riding of horses was the reason one would wear them. There is no other indication that a man would wear spurs just for the heck of it.

[Fox]

I'm not convinced that we should take the picture to seriously as a whole, though the elements in it are probably reliable enough on their own.

Everything about the two characters in boots screams "cavalrymen", they're clearly not seamen and they don't compare at all to the other civilians in the picture - I'm 90% sure they're meant to be military men, in which case the boots make them cavalry.

What a pair of cavalrymen are doing on a French Naval vessel is the next question... possibly the artist simply intended them to be generic soldiers and gave them boots to differentiate them, maybe he was down at the docks the day a cavalry regiment got shipped overseas, who knows?

[JoshuaRed]

Or maybe they're just stationed at whatever island the sailors are trading at, and have been ordered to assist in collecting the payment for the long ride back to town.

Either way, they are definitely soldiers, not sailors.