 The convoy was joined off the coast of the Spanish Netherlands by a further escort commanded by De Ruyter of between 20 and 30 fighting ships.The exact number of Dutch fighting ships involved in the subsequent battle is unclear, but De Ruyter sailed with 21 warships from all five of the Dutch admiralties, two large Dutch East India warships and six fireships.Additional warships may have joined him on route to the convoy and at least one warship was damaged before te subsequent battle and returned to port.