The Hawaii Superferry is soon to install a high-tech thermal imaging system that could help detect whale spouts more than a mile away and reduce the risk of collisions with humpback whales which migrate to Hawaiian waters annually to mate and calve.

The Superferry routes between Honolulu and Maui means huge potential for collisions with the vessel going through areas that have some of the highest whale concentrations. The Alakai cruises at about 30 knots, or 35 mph, is the fastest commercial vessel in local waters. During the last whale season, the ferry reported seven close encounters with humpback whales, including two near-misses of 15 and 25 feet.

The new Night Navigator 3 system can cut through the darkness to detect whales, logs, unlit boats, buoys and other obstacles. It has three sensors: a high-definition day camera, an image-intensified night-vision camera, and the high-resolution thermal imager that can be used day or night. The thermal sensor can pick up spouts as far away as 2 kilometres and with that capability, a vessel travelling at 30 knots would have two minutes from initial detection to change course.

However while thermal imaging of whale spouts has worked well in arctic regions where there is a significant contrast between frigid air temperatures and whale temperatures, they might not be as reliable in a warm, humid environment where the differences are slight. The waters around Hawai'i are typically rough and the temperature of a whale's skin is almost the same as seawater because the animals are so well insulated. Blows are only a few degrees warmer than the surrounding air and finding marine mammals at night in rough seas is a much harder task.

NOAA Fisheries recommends all boat operators keep to 10 knots in areas where whales are known to congregate but Superferry officials have said that's unreasonable and unworkable for the high-speed ferry. The Superferry was required to apply for an incidental-take permit from NOAA's Office of Protected Resources which involves developing a plan specifying actions that would minimize the risk of harm to marine species potentially impacted by ferry operations. Vessels that travel at night particularly need to be really cautious and in recent years, five to seven boat collisions with whales have been reported annually in Hawai'i, although officials suspect the number of actual strikes is much higher.