Do a quick inventory: How many of your friends do you know because of sailing? Sailing is a theme that permeates my life. More than half of my best friendships either began on a sailboat or strengthened because of time sailing together. I'll bet your social network looks about the same.

At its core, sailing is a classic social network; millions of people sharing a common interest and similar experiences get together in small groups to trade stories.

Contrary to myths and common perceptions, the sailing network is diverse and inclusive, at least on the dimensions of ways and means. It encompasses a wide range of individual interests-adventure, travel, competition, science, endurance, strength, strategy, teamwork, ecology, seamanship and stewardship-on a wide variety of craft: large and small, fast and slow, customs, classics, kits, kites, boards, catamarans and trimarans and, now, foilers.

A common interest, whatever it is, is vital to the strength of a social network. When two strangers find that they like, do or want to do the same thing, barriers fall, discussions are more energetic and interesting, and a new friendship often forms. Common interest stories are the glue that hold the relationship together and keep it vital.

The sailing social network is expanding and changing rapidly in an all new directions. The fastest growing and most active group entering sailing is made up of active outdoorsy adult women, who eventually bring their friends and family. (For decades, most sailing newcomers were boys.) Like the disruptive new technology that reshaped the America's Cup, this new demographic is shaking sailing's traditional institutions to their core.

Throughout the 20th century, sailors usually confirmed their status in the sailing social network by becoming members of yacht and sailing clubs. While a few of those clubs were elite and out of reach financially, about 80% of them were designed to lower the cost of access to boats, water and other people who like boats and water, and can still do that. Yacht clubs are akin to sailing cooperatives; places where folks combine time, money, effort and other resources to improve their social community and their quality of life. Alas, until relatively recently, few clubs were friendly to women. Most were made by and for men and many tried to keep it that way. To be fair, club bylaws gradually evolved and gates have opened to women, but it hasn't been perfect. How often have you heard a codger say that the way to attract boys is to use girls as bait? It makes this father of daughters cringe every time I hear it.

So sailing's adult female newcomer is rightly skeptical that membership in a club is necessary to her sailing. Why fight through a thick residue of archaic attitudes when your mission is to go blast reaching with your friends and then post clips and photos of the experience online.

This raises the question: Are sailing clubs compatible with 21st century social trends?

On one hand, done well, a club is the manifestation of a virtual social network: people sign-in, check the status of friends, make plans for the weekend, connect with newcomers, share images, archive memories and "like" each other's stories.

It crosses both ways. Indeed, a Facebook sailing group feels a lot like a sailing club in the virtual domain: people sign-in, check the status of friends, and make plans for the weekend. Yacht and sailing clubs don't need Facebook to recruit members; Facebook itself is the club for newcomers.

It's worth noting that Facebook and other virtual social networks are businesses that give away free membership in order to sell information about its members or market to them, whereas sailing clubs are often more private places requiring a fee and keeping the business of the members to the membership. While there may be a similarity in how the platforms are used, there is a difference in structure and purpose. Sailing clubs may do well to promote the fact that advertising is not in their charter, and privacy is.

In either the physical club or the virtual group, the common interest is what creates attraction and holds it together. That is, the members must go sailing in order to have stories to share, whether they find their way aboard as a result of a Facebook post or a dockside invitation.

How many of your sailing crewmates are women, and how many are men? How is the ratio different from 20 years ago? For me, the change is pronounced: Sailing in the last century was mostly about the guys; sailing in this century is almost always a mixed affair.

Sailing has changed and continues to at a rapidly quickening pace, but the infrastructure lags, due, at least in part, to a few residual archaic attitudes, especially the one that says that men and women should be separated. Katie Pettibone, a member of the all-female 1995 America's Cup America³ team, said it perfectly at the 2013 International Sailing Summit held in the foreground of AC34: "If they can make boats fly, they can certainly invite both women and men to sail on them."