Tuesday, November 12, 2013

Day 6 @ 8am sailing from Fiji to Kiribati

TIME: 2013/11/12 19:42UTC (7:42AM local)
LATITUDE: 03-09.27S
LONGITUDE: 175-21.25E
SPEED: 4.0
WIND_DIR: E (100T)
CLOUDS: 20% with squall clouds to East
BARO: 1008
AIR_TEMP: 31.1C (88F)
SEA_TEMP: 30.0C (86F)

Flying a asymmetric drifter since yesterday afternoon. It's working well to keep us moving in 3-6 knot winds from 100T on a course that's almost perfect to lay Tarawa, Kiribati. Clear skies overnight, but now we have some cumulus clouds moving in from the east. Looks like it's gong to be another light day with a high potential for squalls. In the cabin at 8AM it's 91F with 67% humidity which slightly diminishes my interest in a cup of piping hot morning coffee.

Update: It's now 9:40am. The wind shifted to NE at 4 knots and we dropped the drifter and went for a swim.  Tarawa, Kirbati is 300nm distant.

Excitement overnight was encountering a 135 foot fishing vessel named the Sho Jin Maru #38 (MMSI 432365000). I noticed the lights and then noticed that our AIS was offline (likely a result of SSB radio interference earlier in the evening), when I rebooted the AIS we were within 4nm of ship and ultimately passed within 1.5nm. They were going E at 5 knots and we were headed NW at 2-6 knots flying our drifter with the autopilot in wind mode.

Autopilot 'wind mode' keeps the apparent wind at a predefined value such as 110 degrees, thereby allowing a sail to maintain proper trim despite shifts in the wind direction and strength. It's a nice feature at night when you can't see the sail and it's like a human steering the boat, but better as it never looses focus or complains about watch schedules.

Wind data currently comes from our Tacktick wireless wind instruments and is fed via a multiplexed NMEA 0183 data stream to the autopilot. I'm not sure what the data rate from the wind instrument is, but it's good enough for slow speed sailing.

I've been thinking about replacing the TackTick mast head wind instrument with a wired NMEA 2000 unit with a super fast data output frequency 20 times per second and directly connecting it the Simrad Autopilot.

That's it for now.