In 1628 the British Admiralty ordered typical sailor's clothing to be issued to men who had been press-ganged. This type of clothing consisted of a canvas doublet and breeches, knitted caps ( like Monmouth cap) cotton waistcoats and drawers, stockings, linen shirts and shoes.
Slops (from sloppe ~ breech) were first officially issued in the Royal Navy in 1623 towards the end of the century they became wider and wider.
Artillerymen with Monmouth caps would be a good base for sailors . Add some wide slops and you have nice seamen.