Once the fleets were close enough, exchanges of missiles began, ranging from combustible projectiles to arrows, caltrops and javelins. The aim was not to sink ships, but to deplete the ranks of the enemy crews before the boarding commenced, which decided the outcome. Once the enemy strength was judged to have been reduced sufficiently, the fleets closed in, the ships grappled each other, and the marines and upper bank oarsmen boarded the enemy vessel and engaged in hand-to-hand combat. On Byzantine galleys, the brunt of the fighting was done by heavily armed and armored troops called "hoplites" or "kataphraktoi". These would attempt to stab the rowers through the oarports to reduce mobility, and then join the melée. If boarding was not deemed advantageous, the enemy ship could be pushed away with poles.