I am preparing for stage 1 of the 8 bridges swim in the Hudson River. It is 18.3 miles. I have been doing 4,000 yards 5 days a week, then, adding a long swim on the weekends. I plan on adding yardage to that long swim each week. My question is, what should be my yardage/mile goal for the last long swim before the race? Would it make sense to swim 2 a days? I live in Pittsburgh, Pa, so, open water swims is not an option until May...any suggestions for preparation would be welcome. Thank you. Judy