Airships over the North Atlantic gap

If airships remained in development, how useful would they be in closing the North Atlantic gap?

They could provide persistent reconnaissance, help convoys avoid wolf packs, and offer cover for intelligence derived from Enigma, but their size and low speed would make direct attack hazardous.

Airships could contribute reconnaissance and warn of U-boat wolf packs forming ahead of a convoy. Their visible presence could also provide a plausible explanation for rerouting a convoy whose real warning came from decrypted Enigma traffic. The answer expects them to make some genuine sightings as well. Direct attacks would be much more hazardous because an airship is a large, slow target. Rockets or another weapon usable from standoff range would be needed before it could attack without approaching so closely.