Not really far. It’s a real stretch to think Germany could ever be a naval power. Their position is only marginally better than Russia’s.
The can get into the Baltic and North Sea. That is it unless they can beat the Royal Navy and force their way into the Atlantic, or down the Channel.
They can get out as some kind of stunt as they did once or twice, but they have no capability to come and go as they please, and to protect sea lanes.
Their U-boats almost bought Britain to it’s knees in WW2. Without America aid Britain would have been done for.
Well, I’ve been on the North Sea from Norway and sailed from the huge German seaport of Bremerhaven to the USA and back a couple of times.
Landlocked is landlocked. Germany is far from landlocked.
Their access to the Atlantic proper (from two separate routes) made the German navy a huge factor in WWII.
I had other issues with the article.