What I've seen in DC back in Moscow and missing here - a real diving club atmosphere... Some DC over there (not all of course) keep their own small cafeterias/bars, where people can meet in person, drink something (beer or even stronger), share emotions about their trips and simply talk about life, diving, etc.. Some clubs even have their own small kitchens and people can have a dinner, if they came to club hungry, after busy day at office... These DC cafeterias aren't working every day, but only on "club days" - for example each Wednesday or Friday, etc... Clubs usually have original, SCUBA-diving inspired design - i.e. old-style diving equipment, maps and navy charts, nice UW photos on walls, ship bells, etc.. Members are often contributing small souvenirs from their SCUBA trips.
While people are socializing - DC's shop is always open and people can buy whatever equipment they need...