[4][dead link‍] In 1985, at the age of 15, Mendelblatt was part of a five-person U.S. Optimist dinghy team, along with his brother Mark, that took third place in the 25th International Optimist World Championships in team racing in Finland.

[2] In 1987, Mendelblatt and Caj Flynn won the Bemis Cup, the most prestigious junior sailing race in the US, in Massachusetts.

[2][13] In 1989, at the age of 19, he teamed with his 16-year-old brother Mark to outrace 21 other entries and win the Laser II North American Championships in Maryland.

[14] In 1990, he was honored as first-place skipper in the Laser II North American Championships.

[16][17] In 1995, Mendelblatt won the United States Sunfish Midwinters with a near-perfect score, against 88 other boats.