• 212F Water Boils
• 95F Hot Bath/Shower
• 80F Swimming Pool
• 63F San Francisco Bay Water Temperature (Summer)
• 47F San Francisco Bay Water Temperature (Winter)
• 32F Water Freezes

When folks ask me why I swim in cold water without a wetsuit I answer like this.

5 Reasons Not to Wear a Wetsuit

1. Because we can’t… Swim competitions and Official channel crossings forbid wetsuits because they add buoyancy and give an unfair advantage compared to swimmers who swam prior to the existance of wetsuit technology.
2. Because we don’t want to… Wetsuits are constricting and uncomfortable to wear.
3. Wetsuits are a drag to put on a take off.
4. Sauna feels better the colder we get.
5. When you gotta go, you gotta go, but not in a wetsuit.

  

  

A shout-out to my high school friend Michelle Macy who posted a similar post on her blog.

  

  

I’ve always thought that Antarctica will be the most physically difficult expedition of all our 7 10DL expeditions. Until now I never had a structured way of thinking about how to measure “difficulty”. From a energy expenditure perspective, Antarctica will be the hardest. Here’s how I performed my calculations. 

1. The first step is to breakdown the activities of 10DL. The 10 Degrees Latitude is an expedition series that consists of 5 sports. Those being:

• Cycling 
• Open water swimming
• Kite assisted skiing cross country
• Hiking cross country
• Kayaking

2. The second step is to assume that calorie count is a proxy for “effort”. It’s possible to make a caloric estimate for each expedition assuming the athlete is 190 pounds and that each activity consumes a predictable amount of calories per hour at high exertion. Using this method we can figure out which of the 10DL expeditions is “hardest”, by virtue of the caloric expenditure required to complete it. The source for the calorie count information is here.

3. The third and last step is to type all this into Excel. The results show that the caloric expenditure ranges from the lowest of 57,500 calories in 10DL Australia to 138,000 calories in 10DL Antarctica. It’s not surprising that Antarctica is one of the hardest, and that calorie estimate doesn’t even take into the account the cold temperature, which will consume even more calories as our bodies try to keep warm. Below is the model I used.

The mental side of the “difficulty” equation is much more difficult to measure. I don’t have a measure for that.