[Fidd]

43. Minefields. These should come in several forms:

1. Mines at depth 40m to near sea-bed, anchored to sea-bed, over which shipping may safely pass.
2. Mines at 40m or less, anchored to sea-bed
3. Mines at surface to 20m anchored to sea bed.

Maximum depth (anchor depth) in which mines are sown being 160m(?).

Class 3 minefields are known, and visible on map (as an area) on map. Classes 2 and 3 are settable in workshop mission and are not visible on map. If shallow enough mines and cable may be viewed underwater by OP/AP, or OP/OP/UZO/Binos/naked eye if surfaced, and the mine is at the surface.

Progress through minefield characterised by occasional graunching sound of cables running along hull, possibly drawing a mine down onto the hull if snagged on obstruction on u-boat. Alternating astern and forward on e-motor may allow release of same. A mine detonating results in "destroyed by mine" on end-screen. Mines on surface move up and down with wave action. Very occasional free-floating mines may exist in minefield of any type.

As mine-fields require a sea-bed depth of 160m(?) or less, they're predominantly employed in coastal-waters, and either dropped by minelayers or minelaying submarines, or by aircraft. They are often employed to deny an area to surface craft such as the straits of Dover and northwards toward Zeebrugge, or the northern and southern side of the western approaches, These latter two were further protected by class 1 and 2 types as an anti-uboat measure, and successfully sank a number of u-boats.

I see the value in such minefields being in (one day) workshop coastal missions, where single boats can operate in coastal waters around the UK and Ireland going after smaller convoys, often unescorted, or for missions such as getting into Scapa.