Question: Mobhack - boat design

[zastava128]

Just three quick questions about designing boats/ships:

1. Is swim (movement stat) calculated the same way as for ground units, i.e. max speed in km/h divided by 3?

2. Are there any guidelines for determining the size stat of ships/boats?

3. What's the armour rating for unarmoured wooden hull vessels supposed to be? Two? (the boats I had I mind did have two rows of thick planks with sand in-between to protect their crews)