I think one could go a bit further than that (since it is a house-rule atm anyway).
In terms of Combat I can imagine 3 working scenarios within this game system:
– Offensive Minelaying – Block enemy shipping routes (Use the available Vessels/Aircraft to deploy mines in enemy waters and retreat[lay 4 mine marker in the enemy half of the battlefield within 12″ of the center = Submarine sectors 8-9,9-10 or 10-11])
– Defensive Minelaying – Protect your home-waters (Your Vessels have laid a stretch of mines in your own coastal waters to force enemy fleet movement- destroy any approaching vessels[a bit like “Defense Line” but you may place 4 mine markers in a 6″x12″ area in the centerline of the board)
– Mine Sweeping/Breakthru – Find a way to the open sea (The enemy has laid a minefield to block your fleetmovement – force a way thru the minefield [Basically the counterpart of Defense minelaying – “Breakout” with mines]
Carrying Mines is very easy to implement on larger vessels since you basically just need a ramp and cargo space, but especially U-boats, planes and E-boats(motor Torpedoboats) can only carry limited amounts and usually have to switch mission specific or where constructed especially for this mission(like Kriegsmarine Type X Minelayer U-Boat). I think Refits are a way to make this worth considering (f.ex. remove z number Torpedo for -20 and add x mumber of Mines for +20 points).
Mine-laying can be achieved same way as smoke-screen(they are for the most part just dropped and anchor themselves with the attached mechanic). Give an order in the movement phase(Apply Speed limit of 4″ max speed and propably just AA guns working). Lay one marker for every 3″ distance the ship moves in that phase. Mines may not activate during the round of placement.
Mine clearing during operations for the most part is detonating visible mines after cutting cables and then shooting it when it is on the surface or by triggering it with magnetic fields. Sometimes surplus boats where used to detonate mines. Therefore mine sweeping is actually harder and takes much longer than laying mines and is thus harder to implement.
