Earlier snorkels change fleet building more than ASW doctrine

How would widespread snorkels in the 1930s change submarine development and anti-submarine warfare?

More navies would build snorkel submarines and more escorts, but existing confidence in ASDIC would delay doctrinal change; German output would still be constrained by dysfunctional procurement.

Widespread snorkels in the 1930s would encourage more navies to build submarines able to remain below the surface for longer periods. Greater submarine numbers would in turn drive larger sloop and escort programs. Anti-submarine doctrine would change more slowly because several navies believed ASDIC already gave them a workable answer and underestimated its limitations. German output would still depend on procurement institutions, so a useful technology would not by itself overcome the failures of the office controlling the naval construction program.