Posts from Dec 2013

Sub-100 Swims

Dec 06 2013

Sub-100 swims: Also known as “winter” for San Francisco open-water swimmers.

A sub-100 swim is when the water and air temperatures (in degrees F) sum to less than 100. For example, 50 degree water + 50 degree air = 100 exactly.

For our metric system friends, a sub-100 day conveniently converts to a sub-20C day, precisely.

Like much of the western U.S., San Francisco has been experiencing a bit of a cold snap lately. This morning at Aquatic Park we had 51-degree (10.5C) water combined with 37-degree (2.8C) air, for a combined total of 87 - which, I think, is a new all-time low for me.


I swam with my 6:30am group for our typical 45 minutes. Tellingly, the South End men’s showers were already running lukewarm when I arrived.

The concept of a “sub-100 swim” derives (as far as I know) from fellow South Ender Gary Emich. On his way to 1,000+ Alcatraz crossings, Gary noticed that 100 degrees combined air+water was a threshold below which his morning swims with the ASSes (which often include a dripping-wet post-swim RIB ride) became rather… challenging.

I’ve suggested on the Forum that one way to quantify how cold you are after a swim is to time how long it takes to re-warm in the sauna.

I discovered another method this morning: How many attempts does it take for me to open the combo lock on my locker? I wonder, by February will I have to ask for help? 🙂

I hate winter swimming; I love winter swimming.

Dec 20 2013

In life it’s often necessary to convince oneself to do something one doesn’t want to do, in order to realize future rewards (physical, financial, emotional).

I experience this life truth in microcosm, every morning I swim in San Francisco Bay in the winter. I hate getting up early (I’m a night-owl - always have been). I hate it even more when it’s dark outside; even more when it’s cold outside. And most of all, when the reason for doing so is swimming, nearly naked, in 49-degree water.

Yet it must be done. Because no one ever says, “I really regret swimming today.” Even when the water’s 49 degrees. Perhaps especially when it’s 49 degrees.

Immersion is painful. There’s no avoiding it, even with repetition. Yet nothing makes me feel more alive. And there’s a reason for that: Pain is my body’s evolved, automatic response to encountering an environment that cannot sustain human life. “GTFO,” my body says at first.

When I refuse, the pain fades after a few minutes, and in its place arises a powerful warmth, which keeps the forces of death at bay (for a while). Nowhere am I more closely in touch with my life-force than while swimming in cold water.

The warmth doesn’t stop when I stop swimming. It suffuses the rest of my day in a glow of vitality.

Winter swimming is pain; winter swimming is pleasure. The latter made possible only by the former. Winter swimming is life, magnified.

aquatic park flag

The "Flag." Aquatic Park, San Francisco, California.

Relevant Article