Some Basics 2

The English Channel is 21 miles (c 32 kilometres) at the shortest crossing however the tides play an important role on the final distance. Slower pace, more impact from the tides. The pilot (I will have a boat with me at all times) will aim for a consistent compass heading so that my track will be a "straight" line, even while the tides sweep from side-to-side as the water ebbs and floods. In other words, I will likely make an "S" path easily adding five-miles or more to the swim.

By comparison, Berkeley to Stanford is about 38 miles.

As for time, I anticipate something around 12-hours but it is difficult to predict since the weather, tides and pace all impact the crossing. One can also miss a tide and get stuck until the tide reverses, as it does every six-hours, a main reason swimmers fail. This can happen, most cruelly, a few kilometres from the French shoreline. 

The July/August water temperatures should not be a difficulty at 17-18C and I have been training in temperatures as low as 10C during the winter (any colder and it's a wetsuit) plus cold baths and showers. 

The below is a classic crossing: