Same Water, Different Worlds: A tale of two swims in San Francisco Bay

Last weekend I had the pleasure of escorting Cathy on a big, cold swim in San Francisco Bay to celebrate her birthday. We’re calling it the “Three Bridges” swim: She swam from the Third Street Bridge in McCovey Cove (the original location of the South End Rowing Club in 1873), under the Bay Bridge, and under the Golden Gate Bridge, before finishing at Kirby Cove on the Marin Headlands.


8.7 miles in 2 hours, 10 minutes (with a push from the ebb tide) in 51-degree water, without a wetsuit. It was a damn impressive, inspiring swim, and I’ve never seen Cathy swim so well. She seems totally at home in cold, rough water – and indeed she seems to thrive, the worse conditions become.

With El Sharko‘s steady hand at the tiller, I managed the feedings and aimed my GoPro:

Cathy’s “Three Bridges” SF Bay Swim: 3rd St, Bay Bridge, Golden Gate from Evan Morrison on Vimeo.

Some interesting and sad context to Cathy’s swim: It was (coincidentally) the same morning as the Escape from Alcatraz triathlon, during which one of the athletes died in the swim leg. At 2:01 in the video above, you can see the San Francisco Belle that would soon ferry the Escapees to the Rock for the start. As shown at 3:04, we passed by Alcatraz only a few minutes before the race start.

In a subsequent discussion on SlowTwitch, there was lots of hand-wringing about the frigid water temperature and choppy conditions.

Yes, it was cold and choppy out there. This is San Francisco Bay we’re talking about. Yet it’s impossible not to draw the obvious comparisons: These people were wearing wetsuits! They were in the water for maybe 40-45 minutes on average. Cathy was out there three times as long, without a wetsuit.

And she loved it! Watch Cathy’s video again (2:56) — look at the joy and confidence in her stroke as she plows through the chop. This is how she chooses to celebrate her birthday!

Now watch this video, from the Escape:

These people are in way over their heads. The guy at 0:10 can hardly swim! What the hell is he even doing out there? These two swims took place in the same water, literally minutes apart in time. Yet they might as well be from different worlds.

Here’s a semi-rhetorical question: Which event do you think was safer? The nearly-9 mile, 2+ hour swim without a wetsuit, or the 1-mile wetsuit-assisted swim?

In my view, there’s absolutely no substitute for proper training and preparation. Cathy was prepared for this swim; many of these triathletes, evidently, were not. A wetsuit is not going to keep you safe. Swimming competence will keep you safe.

While wetsuits may decrease the chances of an individual person drowning, I believe they actually increase collective risk – by giving people a false perception of safety and encouraging them to put themselves in situations they are not prepared for.

What is the speed advantage of a wetsuit?

Everyone knows wetsuits help keep you warm in cold water. Lesser known among the general public (but well-known among triathletes) is that wetsuits also make you swim faster! The buoyant neoprene in a wetsuit floats a swimmer higher in the water, decreasing drag and thus increasing swim speed.

But how much faster is a wetsuit? I’ve heard various rules of thumb: 10% speed increase; 4-6 seconds per 100m; 1 minute per kilometer. I’ve also heard various caveats: it depends on the swimmer’s skill (better swimmers benefit less); it depends on the swimmer’s body-type (naturally floaty people benefit less); it depends on the quality of the wetsuit (you get what you pay for); it depends on the fit of the wetsuit; and so forth.

So the answer is: It depends. Because I’m usually disinclined to let things go at “it depends,” I decided to conduct a field experiment. Reef & Run, which I’ve written about previously, provided the perfect laboratory. Almost every Thursday evening between June 21 and yesterday, August 23, I swam one mile in the ocean at East Beach in Santa Barbara. Two weeks were canceled because of shark sightings, and one week I was sick – leaving a sample of 7 swims.

The swim took place at the same time each Thursday: 6:30pm. The conditions were generally similar: low-mid 60s water temp; winds out of the W or SW, producing moderate surface chop and a W-to-E current (i.e., head current going out, tail current coming back). I would characterize them as “rough water conditions” – the view in the above photo is typical. The course was identical each week – a full mile (1609 meters) measured with GPS, and marked by permanently installed buoys.

Generally, I had done a full workout earlier in the day, plus one lap of the course as warm-up. So, for each of these races I was warmed-up but perhaps a touch fatigued. In any case – pretty close to an ideal setup for my field experiment.

My wetsuit is a cheap-o XTERRA Vortex sleeveless, which frankly doesn’t fit me very well. So – a conservative test of the wetsuit effect. Presumably, I would be even faster in a high-end, well-fitting, full-body wetsuit.

Me in the orange cap. Three-time Olympic water polo player Wolf Wigo at left. The two others in the photo were doing a different race. Photo by Mike Eliason, Santa Barbara News-Press

Of the seven races, I wore a wetsuit for four of them and went “naked” for three of them.

My wetsuit-assisted times were: 19:52*, 20:02, 20:14, and 20:14.

My “naked” times were: 21:36, 21:37, and 21:41.

* For the purpose of this analysis, I’m throwing out the 19:52 wetsuit-assisted time. That was the season opener, and it was different in several respects: gorgeous, flat conditions; bigger, more competitive field (thus more drafting opportunities). I’m not surprised I was substantially faster that week.

That leaves a sample of six times – three wetsuit-assisted and three “naked.” My average wetsuit time was 20:10, with a range of 12 seconds. My average “naked” time was 21:38, with a range of 5 seconds.

So, according to my field experiment, my personal “wetsuit effect” – even with an ill-fitting cheap-o sleeveless – was 1 minute, 28 seconds in an open-water mile. That converts to 5.5 seconds per 100m, or a speed effect of 7.3%.

Any other self-experimenters out there? Please leave your data in the comments!

A final word on wetsuits (in marathon swimming)

A few more volleys in the debate, from:

First, thanks to Scott for the generous mention of my post from a few days ago.

In Dave’s response, he emphasizes maintaining a clear distinction between channel-rules swims and performance-enhanced (i.e., wetsuited) swims, but stops short of agreeing with Scott that wetsuited swimming “isn’t swimming.” An important question remains:

If wetsuited swimming is “swimming,” what specifically distinguishes it from channel-rules swimming, and how does this affect how we judge achievements in each category?

Continue reading “A final word on wetsuits (in marathon swimming)”

Follow-up on wetsuits

See original post.

I think Gords makes an important point: that there’s a fine line between valuing the purity of “naked” open-water swimming, and self-righteousness. The latter alienates people, pushing them away when we should be welcoming them and trying to build our sport.

To be clear:

  • This discussion is primarily about marathon swims – which I’ll define as swims long enough to require a support craft. In practice, this usually means swims longer than 10K. Swimmers who attempt such swims are – or should be – sufficiently skilled and experienced that drowning-prevention is not a valid excuse for using a wetsuit. (Hypothermia is a separate issue.)
  • I have no problem with newcomers to open-water swimming utilizing wetsuit technology to ensure safety, to enhance comfort, and to develop confidence. I believe wetsuits encourage more people to try open-water swimming than would otherwise, and that this is positive.
  • I have no problem with wetsuits in triathlon. I’m not a triathlete myself, but they’re certainly free to run their sport however they wish.
  • I have no problem with swimmers of any ability using wetsuits in training swims, or leisure swims, to help them swim for longer in cold water than they would otherwise, or to extend the training season. I’ve done this myself – specifically, last December in Santa Barbara, with my friend Rob D. My cold-water acclimation has since improved, so I’d probably make a different decision now.
  • I have no problem with people using wetsuits in races in which wetsuits are specifically allowed (even encouraged) – such as many open-water races in the UK (including the Dart 10K, recently swum by my friend IronMike), and most open-water races in the US organized by triathletes. Again, I’ve occasionally worn a wetsuit myself in such races – including the Nite Moves swims in Santa Barbara. It’s annoying to lose to people just because they’re wearing a wetsuit and you’re not.
  • However, as I’ve said before, I believe the above policy creates an unfortunate arms-race dynamic, such that people who’d prefer not to wear wetsuits are incentivized to wear them in order to compete.
  • I also understand there are parts of the world (max water temp < 15C/59F) where significant “skin” participation is simply unrealistic. Frankly, though, if they can do it in Alaska, they can do it just about anywhere.
  • I have no problem with open-water races that offer separate divisions for wetsuits and “skins” – e.g., USMS-sanctioned events. In fact I think they’re great – they encourage participation by offering a wetsuit option, while avoiding an arms race.

What many marathon swimmers, including myself, have a problem with is people who specifically market themselves to the media as marathon “swimmers,” who claim to set records or pioneer new swims – yet who use artificial aids (such as wetsuits) during their swims.

In Scott’s words, it’s “wrong, wrong, wrong!”

On wetsuits in marathon swimming

UPDATE 9/8/2011. Please read my follow-up post.
UPDATE 9/12/2011.
Another follow-up.

What’s Wrong with Marathon Swimming” is the title of a recent op-ed/essay/rant by Scott Zornig, president of the Santa Barbara Channel Swimming Association. Zornig’s piece, distributed through the SBCSA mailing list and Facebook page, has sparked some interesting discussion – but frankly, I haven’t heard many opposing voices. Shows who my friends are, I s’pose.

Three issues, basically, moved Scott to wield his poison pen:

  • Wetsuits. Specifically, the use of them during marathon swims.
  • Bootlegging – i.e., attempting a marathon swim without paying dues to the relevant governing body to have it officially observed and ratified.
  • The misuse of the media. In particular, people who use the media to promote and glorify marathon “swims” in which traditionally accepted Channel Rules are not followed (e.g., wetsuits). Especially when such people claim to be the “first” to accomplish a swim, or to have set a record.  Or really, any claim to status, of any sort.

Continue reading “On wetsuits in marathon swimming”