Noticed some U-boats while leaving port (Kiel)

Started a new campaign using a type IIa out of Kiel in 1939 and I noticed some U-boats entering/leaving the port. I think I saw three of them altogether and all of them were sufaced with crews manning the bridge station. I am using the RUb 1.44 version with Sub Commander v2.0 as mods. So my question is, are these U-boats null and just for decoration or do they actually participate in the war? Do they submerged if an Allied ship is near and attempt to sink it, or do they just keep on sailing on? Also, will we see these U-boats in random areas a long ways from the Axis Ports?