In the centre is a States yacht ('statenjacht', a vessel used by the 'States General', the Dutch chamber of provincial delegates in The Hague) with Dutch colours and the arms of the Province of Holland on her stern.
In the right foreground there is a 'kaag' (a Dutch vessel with a straight raking stem and clinker-built). A Dutch ship with the Dutch colours at the main is further away to the left, with a large 'weyschuit' (a Dutch open boat with a straight raking stern, usually rigged with a sprit) in front of her
The picture was probably painted, partly by Willem van de Velde the Younger, for the van de Velde family studio.