Imperial Germany had "Seebattalionen" to conduct operations in overseas colonies during WWI. When WWI ended and the colonies went away, so too did the naval infantry. Nazi Germany entered WWII without any traditional naval infantry.

Kriegsmarine Sailors were employed in land combat roles several times during WWII because of circumstance.

The Germans landed infantry from ships in addition to airborne forces during the invasion of Norway. During the battle of Narvik, Norway in 1940, stranded German sailors from several sunken destroyers were organized into ad hoc formations.They served in defensive roles freeing up the more capable Heer soldiers for combat operations. Interestingly, the naval landings at Narvik were conducted by mountain troops.

Ad hoc formations of sailors were used in contingencies in Sevastopol 1944, Brest 1944, Bordeaux 1944, and in repelling the Dunkirk raid in 1942. These were flexible, untrained formations formed out of desperation.

1945 saw the first official attempts to create "Naval Infantry Divisions." These really were neither division strength, nor purely navy, nor really infantry and were by no means an attempt to develop a naval infantry with any competency in conducting offensive amphibious operations.

These naval divisions numbered 1st, 2nd, 3rd, 11th, and 16th Naval Division were formed from training cadres, administrative personnel, and ship's crew who no longer had a vessel to serve on. They had little if any artillery and anti-tank support. They most likely served as town garrisons, if they existed off paper at all.

The German army did have several unique pieces of equipment they used in small scale amphibious operations. Planning for the invasion of the UK produced modification kits allowing tanks to be submerged but they never saw widespread use beyond tests and perhaps some use crossing rivers in Russia.

Source: "The German Order of Battle: Waffen SS and Other Units in World War II" by George F. Nafziger Pg. 205