Safety - Pacific Crossing Notes: A Sailor's Guide to the Coconut Milk Run - page 63

15-digit alphanumeric code that is printed on the EPIRB. This is the code that is actually
transmitted by the EPIRB when armed and received by shore stations within the GMDSS.
It is different from the MMSI, which is a virtual number assigned to the boat against
which the EPIRB is registered. By making other boats in our vicinity aware of our EPIRB
ID, these boats can also confirm the plausibility of a distress call without having to rely on
someone making a cross border database lookup for our MMSI and emergency contacts.
They would likely learn of the distress via one of the SSB nets such as the Pacific Sea-
farers' Net. We found that news travels very fast and effectively across the various radio
nets.
Q: Do you have an AIS unit? If so, what class unit?
A: We have a simple stand-alone AIS receiver that gets its signal from a VHF antenna
splitter. We found it useful in the North Atlantic, particularly in being able to hail ships by
name on the VHF rather than the vague “vessel in approximate position …” Overall, the
AIS was far less useful to us in the Pacific, where the few freighters or fishing boats we
saw did not have operating AIS units.
We do not use our AIS as a means to detect ships. Instead, we rely on visual watch on
deck and radar in restricted visibility. For one thing, we are sure our simple unit can miss
targets by alternating reception between A and B channels. In addition, we encountered
very few large commercial vessels in the Pacific once we left Panama behind. Since we
cannot rely on AIS detection for smaller fishing boats (or larger vessels fishing illegally
without transmitting an AIS signal), we use it only as a source of additional information
once we notice another vessel via other means. AIS only really came back into play as a
useful tool along the east coast of Australia.
Q: What types of weather services do you use when making an offshore passage? How do
you gather weather info?
Markus: We basically use three sources for our weather information. First, we try to get
synoptic charts (surface analysis and forecast) via radio fax (or the Internet before depart-
ing for a passage). These provide us with a good idea of the “big picture” and relevant
meteorological details such as fronts, troughs, and convergence zones. Especially before
longer passages, we try to follow these charts consistently over one to two weeks to get a
feel for the rhythm of weather patterns and how well the forecast matches reality.
Second, we use the output from NOAA's GFS model via Saildoc's email service in two
forms. One is a moving spot forecast three or four days out with wind and wave data. The
other is a longer term outlook (seven to ten days) on surface pressure via GRIB files over