The convoy is moving at a relatively sedate pace, especially compared to his ship, and don't seem to be in any hurry to flee when he looks like he's trying to engage, and he'll manage to catch up to them in less than an hour. As soon as he gets in range, though, he'll have several catapult shots fired in his direction; likely warning shots, more than anything, directing him to stay clear, though they're likely pretty confident that his one ship can't capture all three of theirs.