Well, the cannon only needs to produce enough force to move a tiny cannon ball really fast.
The 6 second interval is to match the in game fight sequences, implying that the enlarge spell would finish casting as it impacts the enemy ship. All of that momentum suddenly comes to a grinding halt as the weight suddenly changes and the cannon ball rips the enemy ship to shreds
Well, the cannon only needs to produce enough force to move a tiny cannon ball really fast.
The 6 second interval is to match the in game fight sequences, implying that the enlarge spell would finish casting as it impacts the enemy ship. All of that momentum suddenly comes to a grinding halt as the weight suddenly changes and the cannon ball rips the enemy ship to shreds