Saturday, 16 August 2014

"Beyond Seabreeze", OSCAR GRIBs and Winmor HF

Hi everyone,
This morning we attended an excellent 3 hour talk at FSC presented by Lynath Beckley and Jess Sweeney.  The talk described an array of web sites providing current, tide, wind and weather information for sailors.

One of the items which came up was how to obtain ocean current information when at sea without internet access.  The software program Expedition is able to download GRIBs (via HF or satellite) showing ocean current information from the OSCAR satellite system.  For those without Expedition there is sv Sarana.  Eric and Sherrell of sv Sarana have set up a SailDocs-like system which sends you a GRIB file in response to an emailed request (again via HF or satellite).  See their web site for the full details.

Here's an example 8KB GRIB file retrieved today...

GRIB file of OSCAR ocean currents from sv Sarana
Note that not all GRIB display programs can render all types of data, and OSCAR data is one of those which is least well supported.  We use qtVlm which is actually a routing program which includes nice GRIB display.  Routing programs use weather forecasts in GRIB files and polar diagrams of your yacht's performance to calculate optimum routes from A to B.  qtVlm is free!

At sea we normally obtain GRIB files using our PredictWind Satellite Communicator's email facility.  However we still have our HF radio system which can also do this job.  We plan to move from a Pactor modem-based HF system to the Winmor software-based HF system.  Winmor is a relatively new and much cheaper option, but is currently only available to Amateur (Ham) Radio Licence holders.  Hardware costs drop from $1500-$2500 to about $150.  The fancy signal processing is done by your laptop instead of costly hardware.  Winmor is about half the speed of Pactor 3.

Here's a picture of one Winmor window....

Winmor's Sound Card TNC window
So far we've installed the hardware and software, and done basic system setup.  We'll need to get the boat out of the pen to actually try it out.  The nearest Winmor-capable Winlink stations are in Victoria and NSW, similar to the nearest Pactor-capable Sailmail stations.   More on this in due course.

Other events since our last post include taking part in a FSC Winter Inshore Series race.  Winds were light but we completed the course.  Twas a learning experience since we haven't raced for several years.  We discovered we had no description of Naval Numeral flags aboard so didn't know what course.  We mistook the class flag and were late to start.  Nevertheless we had a great tussle with the Bavaria 37 "Glass Hopper".  The wind was E-SE.  Here's our speed profile and track...

Zen Again speed
Zen Again track
Some of those tacking angles are very ugly!

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