November 11: A day of fast sailing on a good heading
Posted on November 11, 2012
Nov. 11 Sunrise:
Last night, we made 116 nautical miles (averaging 9.6 knots) on a heading of 12 degrees True (Haka Ko’olau). The last several days of available easting, combined with a favorable wind shift from north of east to south of east, moved Captain Bob Perkins to change course to 350 degrees True (Haka Ho’olua), a heading more directly toward Hilo. We will still navigate to a point east (upwind) of Hilo to be safe from ending up downwind of our destination, but we believe we can basically “head for home” at this point.
Celestial Observations, Navigation Stars, Planets and Moon Phases (See Hawaiian Star Lines for star names and configurations.)
6 pm to 10 pm watch-Our watch had good stars all around the compass available for steering, but we had to play hide and seek with them as they hid behind dark black clouds, then appeared for brief periods. It was great training, maintaining two or three steering stars at a time and switching off often as they disappeared.
10 pm to 2 am watch - From our post-equator-crossing reflections we found that our watch really wanted to step up our navigation training, so tonight with starry, clear skies, we went to Navigation Bootcamp.. We divided our four person watch into four stations: Navigator, Steersman, Speed, and Rest. The stations are rotated every 30min. Here are the kuleana of each position: Navigator – set the course and give the steersman his/her mark. Requires knowledge of star declinations and calculation of our desired heading based on the known star declination. Steersman – hold true to the course set by the Navigator. Requires a good feel for the movement of the canoe. A good steersperson can anticipate the swing of the wa’a and steer accordingly to keep right on target. Speed – this person is estimating our speed based on the time it takes bubbles to pass from our first ‘iako to our last (about 40ft). Speed is distance divided by time. Rest – this person kind of gets to take a break, but they are also responsible for using the computer’s AIS system to place a waypoint at the start of each rotation. The crew did a phenomenal job and honed some really important voyaging skills. Stay tuned for tomorrow’s Bootcamp Part 2.
2 am to 6 am watch- We picked up the watch maintaining a steady course of 15-20 degrees (Haka Ko’olau) with speeds of 7-9 knots. We started out with Achernar behind us in Nālani Kona and the northern meridian pointers of Hokulei aligned with Nāleo Ho’olua. And for the first time we were able to briefly see Hōkūpa‘a (Polaris, the North Star), just above the horizon. As we moved further into the northern hemisphere, now well above 3 degrees of latitude, the cloud cover became thicker, obscuring most of our stars, and swell motion diminished. For a short time we were able to follow the moon, which rose just after 3:30 in Lā Ko’olau but we eventually lost that too as the sky clouded over completely. From then on we followed the motion of the swells and wind direction with its apparent speed to guide us, along with the help of the GPS to ensure we were on our correct course.
Hōkūpa‘a (Polaris) appears due north above the horizon in the northern hemisphere, it’s altitude approximately equivalent to the latitude of the observer. (At 3° N in the graphic above, about 3° above the horizon; in Hawai‘i, at 20°N, Hōkūpe‘a appears about 20° above the horizon.) Nā Hiku (the Big Dipper) appears rising to the east (right ) of Hōkūpa‘a; ʻIwakeliʻi (Cassiopeia) is setting to the west (left).
For Complete Sail and Education Data, see the Tracking Map.
Nov. 10 Sunset:
A day of fast sailing on a good heading with easy steering. Since 6 am, we made 97 nautical miles on a heading of 016 degrees True (Haka/Nā Leo Ko’olau), an average speed of a little over 8 knots. The crew is safe and well. For Complete Sail and Education Data, see the Tracking Map.
Hawaiian Star Compass (Click on the link for an explanation of the names of the directional houses of the compass. Click on the compass for a larger image.)