Although our watch schedule has been quite loose this
passage, we do keep a log with entries at least every hour. The log is a bound
book with numbered pages that can be used in a court of law (ie collision with
another vessel).
It also records our last known position in the event of
loss of navigation instruments (GPS system goes down, power failure, etc.) We
would be transported back to before
1980 and resort to using dead
reckoning, celestial
navigation and paper charts. When Kurt and Harry sailed to Mexico,
Marquesas, Hawaii and back to San Francisco in 1982, GPS was not available to
the public. Positions were determined using a sextant, sight reduction tables
and a chronometer. A noon sight is the easiest but sometimes (as in the first
few days of this trip) the sun is obscured by clouds and its angle to the
horizon cannot be determined. There are methods to get fixes at other times and
using other celestial bodies (moon, stars, planets).
Entries include:
CTS Magnetic Course To
Steer to reach our next
waypoint
COG Magnetic Course Over Ground (the
direction the vessel is actually traveling accounting for leeway and current
as read on the GPS)
BSP Boat Speed (using two
underwater sensors on the hull and keel measuring the Doppler effect)
SOG Speed Over Ground
TWD Magnetic actual wind
direction
WSP Wind Speed (a calculated
value based on BSP and apparent wind speed)
BAR Barometric
pressure in mb
SEA T. Sea Temperature (Interlude has a thru hull
thermometer)
LOG Miles recorded using BSP
AWA Apparent Wind Angle (useful
for setting sails or steering while sailing)
OIL Main engine
oil pressure (it is a good idea to look at the gages to check for anomalies at
least every hour when the engine is running)
HRS Main engine hours
Te
Main engine coolant temperature (to make sure raw
water is flowing and other cooling components are working properly)
Tx
Main engine exhaust temperature (to make sure the engine
is not lugging)
On May 25, 2024, our position at
1200 local
1200 PDT
0700 NZST (May 26)
was:
9d20.1m N, 143d12.7m W
24 hr noon to noon: 218 nm
It is now 95 F in the pilothouse and sea temperature is
85 F. The tropics “makes
her clothes fall off”