But 16km was not the real victory for me.
The difference with this swim was that it was all about the mental battle.
Until now, I have given myself the relative 'luxury' of counting the lengths. Even though counting off 640 laps (the distance I covered today) may sound mind numbing, it is also a way of mentally recording your progress as you go, lap by lap, minute by minute.
But I know I will not have this luxury during the Channel swim. I'll be relying upon my support crew to signal to me by whistle every hour, letting me know that it's time to take a break. In between breaks I will be left to my own devices and thoughts, with no way of measuring the passing time.
So I recently purchased a watch which counts off the pool laps as I swim, allowing me to begin to acclimatise myself to the boredom.
And I can assure you that boredom can be mental purgatory.
I took my first brief refreshment break today at 1hr 13, having covered 3.6km. The next was at 2hr 20. After that, the intervals began to come down, with my mind convinced that surely another hour MUST have gone by.
Long before the 3hr mark, despite being able to regularly swim for 4hrs, I was mentally ready to quit. Every niggle, every rub, every ache, was magnified by the boredom. I had to carefully analyse my actual physical condition as I went, and realising I was not tired and did not NEED to stop, I had to gather my mental resolve and keep pushing.
I don't think I've ever been so bored in my life.
It's always very easy to repeat any mantra when you're not in pain or discomfort: 'Winners never quit - quitters never win'; 'Just keep swimming'; 'It's only pain' etc - but it's simply not possible to do this for six or more hours continuously when such advice really is needed. And it's easy to tell yourself that six hours is a relatively short period of time (much shorter than the 16 predicted hours for my actual Channel swim) - but until you know you are approaching the end of that six hours, trust me when I say that eternity can easily be condensed into such a timeframe.
But mental victory was finally achieved today. I climbed out of the pool far from as tired as I expected to be, but very jubilant that I had resisted the almost continuous and overpowering urge to go and do something, ANYTHING, less boring that even one more lap of the pool.