A recent e-mail message from a Water Ways reader on Maui got me digging through my files for resource materials.

"Now that our humpback whales are beginning to show up for the winter," she asked, "wouldn't it be a good time for you to run through the whale-watching rules for boaters?"

Fortunately, I found my copy of the Hawaiian Islands Humpback Whale National Marine Sanctuary's handbook, which gives all ocean users a behavioral guideline for sharing the ocean with our visiting whales.

For starters, the handbook advises that, as an endangered species, the humpbacks are protected by federal law, and approaching them closer than 100 yards - one football field - by any means, is illegal.

What about when it's the whale that is doing the approaching?

Although that situation is not clearly covered in the handbook, most authorities recommend bringing your boat to a full stop and to allow the whale the right of way. Or, when possible, try to slowly increase the distance between your boat and the whale to the allowable 100 yards.

Either way, the important factors are keeping your boat's speed to a minimum and avoiding physical contact. Obviously, any collision with a 80,000-pound mammal would likely be a lose-lose situation for the boat and the whale.

Along with not giving whales at least 100 yards of clearance, any disruption of a whale's normal behavior is law violation for boaters.

According to the handbook, "disruption of normal behavior" includes a wide variety of actions. Just causing a whale to change its direction or its speed can be interpreted as a disruption.

Furthermore, boat operators must never cut across a whale's apparent course, come between a whale and deep water, or, with other boats, surround a whale.

Disrupting normal behavior can also mean causing a whale to use escape tactics such as, prolonged diving, underwater course changes, underwater exhalation, evasive swimming patterns, or the abandonment of a previously frequented area.

The handbook also reminds boaters that female humpbacks often come to Hawaii's warm offshore waters to give birth and to nurse their calves.

Any boat that comes between a calf and its mother would naturally be a major disruption to them.

In other words, Hawaii's boaters are being asked to give all whales a wide berth.

Because a boat operator's vision may be impaired by wind, rain, or glare off the water, it is always a good idea to run boats at a reduced speed to avoid a collision while the whales are visiting our waters. At best, humpbacks can only swim at about 20 m.p.h. for brief periods (3-6 m.p.h. is their normal speed), so unless they make an emergency dive, they can easily be overtaken and possibly struck.

As the humpback sanctuary laws extend out 200 nautical miles from the Islands, the National Oceanic and Atmospheric Administration's Office of Fisheries Enforcement depends on all ocean users to monitor boaters' compliance with these laws.

If you should observe any vessel being operated in violation, you are requested to contact its office at (808) 541-2727, or at the NOAA Fisheries Enforcement Hotline at 1-800-853-1964.

For more information about Hawaii's Humpback Whale National Marine Sanctuary, call 1-800-831-4888, or write to 736 S. Kihei Road, Kihei, HI 96753.