Now, I am no stranger to swimming long distances. I swam on a club team and on my college team for two years each. At the peak training point in their seasons, both of these teams swam 6 days a week and held "doubles" (i.e. 2 practices a day) on 2-3 of these days. Yet even in our most yardage-heavy practices, the farthest I ever remember swimming in one practice was ~7,500 yards. That is still 50 laps short of what I am about to swim on Saturday.
And that is simply the distance of the swim. Now consider that in a nice clean, clear pool, swimmers can keep their heads submerged and see everything around them, including lane lines and big bold stripes along the bottom of the pool, which keep them swimming in a straight line. In a lake, river, or ocean (my swim will be in a river), the water is murky, which requires swimmers to lift their heads in order to look in front of them--a practice called "sighting." Swimmers must sight in open water in order to a) make sure they are staying on course, and b) navigate around any foreign obstacles including trash, natural debris, and other swimmers. The choppier the water, the more difficult it is to sight...never mind breathe.
Now, even if I felt confident that I could swim 10,000 meters (which I don't, since I've swum no more than 5,500 meters at any given time, none of which was in open water), had ample practice sighting (which I don't, since I have only swum in open water about 4 times this summer), and knew for certain that the water would be calm (which I highly doubt, having swum in the Hudson on several previous occasions, none of which were "calm") there is one more crucial factor to consider: temperature.
A regulation Olympic swimming pool is kept at 77-82 degrees Fahrenheit. As I write this, the Hudson River temperature (at Sandy Hook) is 64-65 F. The last time I swam in water under 70F, I only managed to stay in for 20 minutes and spent the next two hours trying to get rid of the pins-and-needles sensation in my fingers and toes.
So yes, I am extremely nervous about this race. That being said, I find nothing more exhilarating than attempting something completely new. This year's Olympic-distance triathlon was exactly that: an athletic feat I had never before attempted. What I love best about these new challenges is that apart from completing the race, I can hold absolutely zero expectations. There is no precedent, no prior time to beat. Just crossing the finishing line is goal number one. While I do always set a projected goal time, whatever time I finish will be my PR (personal record), so there is no real way to be disappointed.
Looking at last year's results and taking into consideration my training, the water temperature, and the race course (most importantly, river current!), I would love to finish this 10k swim in under 2 hours. However, I think 2:15:00 is probably a more realistic goal. Either way, I suppose I can say that as long as I finish, I won't be disappointed.
...well, not too disappointed.