ASTM F2993-13

3.3.1 Commercial parasailing is prohibited when the current observed wind conditions in the area of operation include a sustained wind speed of more than 20 mph, wind gusts of a difference of 15 mph greater than the sustained wind speed, the wind speed during gusts exceed 25 mph or rain or heavy fog results in reduced visibility of less than 0.5 mile, or when a known lightning storm comes within 7 miles of the parasailing area.

3.3.2 Hawaiian Islands region: due to the consistent nature of the offshore trade winds, operators in this region may operate under a 5 mph allowance to the sustained wind speed for offshore wind conditions only. Onshore wind conditions remain the same in accordance with 3.3.1. Therefore, commercial parasailing may occur in sustained offshore wind speeds up to 25 mph.

3.4.1 Operators in lakes, intercoastal areas, and rivers shall not operate in sea conditions or a wave height that exceed 3 ft. Attention should be given to the specific body of water in these cases as these locations are typically protected areas. Therefore a wave height or water surface condition that meets or exceeds 3-ft waves or chop may be produced by wind that exceeds the 20 mph threshold described in 3.3.

3.4.2 Operators in offshore areas shall not operate in sea conditions that exceed a wave height of 4 ft, unless wave height and period are in accordance with the following calculation: 3 s of period for every 1 ft of wave height (for example, 4 ft = 12 s, 5 ft = 15 s, etc.). Wind speed and payload shall also be taken into consideration at all times of operation. The best evidence of wind and wave conditions within the flying area shall be determined by the vessel Master and may differ from a weather service report.