Cowie convinced the Sultan that to achieve a lasting success in overcoming the Spanish blockade he would need access to a safe harbour; from there he could wait until the shipping route to Sulu was free from Spanish warships.
Cowie convinced the Sultan. This Sultan to achieve a lasting success in overcoming the Spanish blockade. He would need access to a safe harbour the Spanish blockade. He could wait. This is from there. The shipping route to Sulu was free from Spanish warships.