Catapult Attack:1d20+6=14, 1d20+6=20
Ballista Attack: 1d20+4=10, 1d20+4=17, 1d20+4=15
Ballista Damage:2d8/2=6, 2d8/2=6, 2d8/2=6 18 total
Each round Zach must spend a standard action directing the ship and observing the battle.
Each round the helmsman - whoever that may be (probably Groh) must spend a standard action to steer the ship.
Each round the sevven deckhands you hired must spend their standard actions doing various crap needed to make the ship do what it needs to do.
THE WEAPON TEAMS
Each round these guys each spend a full round action loading and firing weapons.