Reading the Osprey book about German Women's Auxiliary Services, I've seen several photographs of sailors from sea being greeted by men and women in uniform when they reach the coast. I wondered which actual services did the greeting-Navy, Army, or whoever happened to be available at the time?

Also trying to find German sailors in shipboard work uniforms. Many of them in fact wore captured British ones.

You're not confusing the M1944 uniform with British BD, are you? The M 1944 jacket was loosely copied from the British one:
http://www.spearheadmilitaria.com/images/v/20110708/ft70001.jpg

To answer the question about greeting, the women are probably Kriegsmarine Helferinnen, of which there were about 20000 mainly working in offices as administrative assistants.
For uniforms, the BD style drill uniform was actually quite widespread amongst U-Boat crews as there was little chance of them being mistaken for the enemy at sea! They were made up from captured stocks of BD material.
However German U-Boat leathers were also aquired from the Italian Navy by the LSSAH during its sojourn there and issued to its tank crews. Either Masterbox or Miniart (I forget which) do a set of tank crewmen wearing them. Since they are not wearing equipment they should be pretty good for U-Boat men without too many changes.