Finally, a Navy Post

The thing about the Heer defeating the Kriegsmarine is that it's something of a silly idea, since the Heer is on the land and the Kriegsmarine is floating like noobs on the water, noobishly. However, I have a solution! Allow me to quote Feldgrau on German long-range capabilities:

"The Germans also had an assortment of rail guns, huge artillery pieces mounted on railroad cars, and self-propelled mortars that crawled about on huge tracked carriages. One such mortar or "Mörser" was the 600mm "Karl" battery. It weighed 132 tons, was 35 feet long, and moved at 3 mph by a 580hp diesel engine. It had a ground crew of 109 men and it could fire a 4,850 pound mortar round that could penetrate 98 inches of concrete or 17-3/4" of armor. The rail guns were even larger yet, the 800mm Kanone "DORA" had a range of 29 miles, a crew of 250 men for assembly and firing and 4,120 men in all. It could fire one 10,500 pound shell that measured 25 feet long plus the length of the case at a rate of 2 rounds per hour. The 280mm KS(E) rail gun was 95 feet long, weighed 479,600 pounds. and could fire a projectile 38 miles. It used a crew of 10 for firing."

Weapons like this can be mounted on the land, but they don't float on the water. And if the Heer can keep the Kriegsmarine out at sea forever, eventually all the Kriegsmarine soldiers will become fishermen instead of soldiers and the German navy will become just a German collection of fishermen with extremely well-armed fishing boats.