What a differencer a day makes

'Sarf & West mate, Sarf & West'
Pete Bernfeld
Wed 16 Jun 2010 18:59
24 little houre etc etc
11:33.742S 143:07.135W
Position at 1830 UTC 16/06/10
The first 24 hours run was 117nm & the second one is shaping up to be about 125nm. Slow, but we're running under reduced sail for reasons I will give in a moment.
Last night was very pleasant; the maximum gusts were in the region of 22/23kts as opposed to 30kts on the first night and there were no squalls, the only thing that spoilt a great sail was a slightly confused sea [oh, where am I, who am I, where am I going?Why did that dolphin say 'turn left'? Oh, I'm just slightly confused].
We've decided to make for the atoll called Mahini, in the NE corner of the Tuamotos group and have about 250nm to go. The slight problem is that the Tuamotos are all atolls, which means there is a surrounding reef and a lagoon in the centre where an island used to be, the highest structure is generally the palm trees and the charts were last updated about 1834! This means you don't get a radar return on the island until you're about 5/6 nm away and they'll probably be in the wrong place anyway (according to the GPS). The upshot of all this is I don't want to be within 10nm of a charted position of any particular atoll during darkness which means juggling our speed to arrive within 10nm of a given position anytime from 0530 onwards. We can't make enough speed to arrive by 0530 Thu  morning, hence the reduced speed to ensure arrival no earlier than 0530 fri morning [assuming of course that the wind doesn't disappear entirely between now & then!]. The forecast is for winds up to 15kts, so provided we average around 5kts (do-able in the forecast winds) we have time in hand. I also don't want to have to stand-off the atoll overnight, the currents are unpredictable so you run the risk of not being where you thought you were when you can finally see anything!
One final wrinkle; the atolls in the main have one pass i.e. entrance into the lagoon. There can be a strong current flowing ut of the pass meaning you have to wait for slack water to get in. There is no reliable method of predicting slack water so it could be you arrive in daylight and have to hang around for six hours before you can get in anyway, fun eh?