November 12: in the intertropical convergence zone, above 5° N
Posted on November 11, 2012
November 11, Sunset:
Today, we entered weather normally associated with the Inter-Tropical Convergence Zone (ITCZ).
Our weather forecaster, Hans Rosendal, told us to expect the main ITCZ activity to be between the latitudes of 5 degrees North and 11 degrees North. He was exactly right. At 6 a.m., we were nearly to 4 degrees North and the weather changes were becoming obvious – more overcast, larger clouds, and “heavier” air.
The best change was the wind clocking around from a more southerly direction. This change, coupled with the forecasts of solid trades north of the ITCZ, has allowed us to turn pretty much directly toward Hilo. We will still aim for arrival about 150 nautical miles east of Hilo to ensure we have a downwind run into Hilo Bay.
The ITCZ is sometimes called as “the doldrums”, meaning no winds and bobbing around. So far, so good – keep your fingers crossed that we encounter no doldrums but just sail right through the ITCZ. Hans also warned of more frequent showers in the ITCZ and that has already proven accurate. Just as we passed through 5 degrees North, we sailed through our first squall. The crew is safe and well and stoked to be heading more directly home.
- course: west of north, heading 353 degrees True, Haka Ho’olua
- speed: 8 to 9 knots, faster in winds associated with squalls
- wind: south of East, 10 to 15 knots, higher near and in passing squalls
- sea state: East 5 to 6 feet, southeast 4 to 5 , both well established
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.)
November 12, Sunrise
Last night, we were graced by consistent, if light, winds – a true blessing in the Inter-Tropical Convergence Zone (ITCZ). Last night, we made 62 nautical miles (averaging 5 knots) on a heading of 353 degrees True (Haka Ho’olua). Not bad, for “the doldrums”, when we were aiming for 350 degrees True (Haka Ho‘olua), our heading more directly toward Hilo. This performance is a testament to the training and development of this crew since we left Papeete, Tahiti, twelve days ago. Especially considering that it is more challenging to steer in light airs than stiff breezes. We must admit, however, that the mellow seas help. We’re doing great so far in the ITCZ and hope for continued good fortune.
- course: west of North, heading 353 degrees True, Haka Ho’olua
- speed: 5 knots
- weather: Abundant cumulus (5/8 coverage). Some sunny clear patches. Some wind-torn mid-level clouds streaming slowly in from southeast. No high clouds. Dry and warm.
- wind: south of East, 5 to 10 knots
- sea state: Southeast 4 to 5, well established. Northeast 1 to 2 feet.
Celestial Observations, Navigation Stars, Planets and Moon Phases (See Hawaiian Star Lines for star names and configurations.)
10 pm to 2 am watch - Clouds, clouds, clouds, that’s what we were working with tonight. For our entire watch we had < 90% cloud cover and light winds of about 10 knots out of the southeast. The winds combined with our movement in the same direction of the swells allowed Hikianalia to swim between 4-5 knots. It can be a lonely thing in the dark night to have few and shifting celestial cues. Because of this we decided to rotate short pieces on the steering hoe, with everybody pitching in to locate, identify, and help hold us on track. The constant rotation on the hoe kept everybody alert and moving, which can be a challenge as the light weather and gentle rocking tries to lull you to sleep. “Good job” goes out to the crew, since our desired heading tonight was Haka Ho’olua, and the digital mapping of our course on the AIS/GPS thankfully confirmed that that was the heading we held despite the clouds.
2 am to 6 am watch- Our watch began with 90% cloud cover but, within the hour, began to clear. We at first had a bit of a game of ‘name that star’ and needed to constantly change our useful steering pointers in order to maintain our desired heading of 350 degrees (Haka Ho’olua, erring preferably towards ‘Ākau [North]). Venus rose in Hikina (East), making our steering much easier as we kept it approximately one house aft of the beam. This was followed by Hikupau (Alkaid), the last star in the handle of Nā Hiku (the Big Dipper), which we kept in the forward starboard shrouds. Hikianalia (Spica) on the eastern horizon once again led us to daylight. We even caught a glimpse or two of Hōkūle’a (Arcturus) between the clouds affirming our position and our ever-northward migration. Saki chose tonight to begin her long hours of sleepless navigator training, staying up all night and helping us to keep our course. We are all enjoying the downwind smooth sailing, and are even able to surf the canoe at times. Even with the light winds, we were able to maintain a speed of 4.5 to 5 knots.