Bob is correct for USMS (as well as NCAA and USA-S) altitude adjustments are only applicable for National qualifying times. Not for Top 10 or records.
The following text and table is from the 2004 USMS rule book:
(1) Altitude adjustment—Times achieved at an altitude of 3000 feet or higher may be adjusted, for NQT purposes only, by subtracting the adjustment times (in seconds) from the actual time achieved. The specific adjustments for each age group and gender are found in Appendix B. The adjustments shall be determined every 4 years starting in 1998. The adjustment times for men and women competitors shall be calculated by multiplying the time adjustment in the following table by the ratio of the 200-yard freestyle national record for the age group to that of the 25–29 200-yard freestyle for men and women, respectively. The values in the following table shall be those determined and used for the same purpose by USA Swimming.
Note: Records and Top Ten, etc., are to be actual times swum, not adjusted for altitude.
3000–4249 ft -- 4250–6499 ft -- 6500+ ft
200 yards/meters -- 0.5 -- 1.2 -- 1.6
400–500 yards/meters -- 2.5 -- 5.0 -- 7.0
800–1000 yards/meters -- 5.0 -- 10.0 -- 15.0
1650 yards/1500 meters -- 11.0 -- 23.0 -- 32.5
With apologies for how the table looks here.
Bob is correct for USMS (as well as NCAA and USA-S) altitude adjustments are only applicable for National qualifying times. Not for Top 10 or records.
The following text and table is from the 2004 USMS rule book:
(1) Altitude adjustment—Times achieved at an altitude of 3000 feet or higher may be adjusted, for NQT purposes only, by subtracting the adjustment times (in seconds) from the actual time achieved. The specific adjustments for each age group and gender are found in Appendix B. The adjustments shall be determined every 4 years starting in 1998. The adjustment times for men and women competitors shall be calculated by multiplying the time adjustment in the following table by the ratio of the 200-yard freestyle national record for the age group to that of the 25–29 200-yard freestyle for men and women, respectively. The values in the following table shall be those determined and used for the same purpose by USA Swimming.
Note: Records and Top Ten, etc., are to be actual times swum, not adjusted for altitude.
3000–4249 ft -- 4250–6499 ft -- 6500+ ft
200 yards/meters -- 0.5 -- 1.2 -- 1.6
400–500 yards/meters -- 2.5 -- 5.0 -- 7.0
800–1000 yards/meters -- 5.0 -- 10.0 -- 15.0
1650 yards/1500 meters -- 11.0 -- 23.0 -- 32.5
With apologies for how the table looks here.
