New Swiss Destroyers 1909

[Korpen]

One thing to have in mind when using early hydrophones, the ship using them cannot have it engines running, or all that is heard is the own ship. the same goes for other ships around it.

[Korpen]

Low vis = dark blue paint. The Johann Wys do have light-absorbing gunk but then they have 50t of misc weight and are experimental plataforms.

Light absorbing also means heat absorbing, I pity the poor sailors aboard such a ship under the blazing equatorial sun and an air temperature of at lest 30C...