As announced several months ago, we were forced to replace our Joinable User Groups system because the software was no longer available. The replacement method is explained in this new thread in the the Frequently Asked Questions forum:
The interim solution for divemasters and instructors has changed back to moderators verifying credentials instead of being handed in Preferences. Some members may have to reapply.
FAQ - Restricted Access Forums
Restricted Access Forums ScubaBoard has a number of forums that require members to take specific actions to access them. These forums also exclude all search engine indexing used by services like Google and Bing. Opt-in Forums (no approvals required) The following forums can not be accessed by...
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The interim solution for divemasters and instructors has changed back to moderators verifying credentials instead of being handed in Preferences. Some members may have to reapply.