C1. Turret to size ratio:
Think about the size of your ship compared to the turrets you want to use. You shouldn't put a Tempest on a small patrol boat etc.
If you're unsure, just check with an admin/moderator.

C2. A. Turret placement:
Turrets should be clearly visible on your ship. Building around turrets is fine, but don't hide them inside props or encase them in a dome etc.
C2. B. Equipment Placement:
This is a bit more complex, so just think about how the peice of equipment you're using would be placed on a real life ship. Just ask if you're unsure.

C3. What vehicles can use which weapons?:
Turrets can be used by ships only.
Torpedoes are available for submarines and ships.
Depth Charges and Hedgehogs are ship only weapons.

C4. What vehicles can use which equipment?:
Fishing nets and Mining equipment are ship only, the same goes for mining containers.
Sonar can be used by both ships and submarines. Have fun in those cold waters.
Air radar is as you guessed, plane only.

C5. SDG Weapon Control:
You can wire all the weapons you have to one chair if you wish, but you might find yourself running out of buttons if you have different weapon types.

C6. Transportation:
You can transport your newly acquired SDG weapons & equipment from the rig via ship, airship and submarine.

These rules will change as time goes on as we discover new quirks and loopholes.