Why the Baltic Project was the only way to tighten the blockade of Germany

Was the Baltic Project the only viable maritime strategy for increasing pressure on Germany?

The long blockade remained the core strategy, and entering the Baltic was the only direct way to close Germany's remaining maritime outlet, but it first required neutralizing the High Seas Fleet and controlling submarine threats.

Britain could already restrict Germany through distant blockade, but the Baltic remained a route for trade and movement that the North Sea cordon did not fully close. A stronger blockade therefore required forces inside or across the Baltic approaches. That in turn demanded disposal of the High Seas Fleet and enough anti-submarine capability to operate in confined waters. For the Second World War, German air power would add another barrier and make the same concept still harder to execute.