If you have a laptop on board your boat, there is no reason why you should not have a redundant chart plotter.
Full write-up:
blog.arribasail.com/2013/10/tech-testing-globalsat-mr-350-gps-with-opencpn.html
If your going to spend $60 or $70 on a GPS puck then buy a new generation Sirf 4 chip unit. These are twice as sensitive and much more accurate than the Globalsat mr 350 which uses the Sirf 3 chip.http://www.ebay.com.au/itm/HOT-SALE-GlobalSat-BU353-S4-BU-353-SiRFIIII-USB-GPS-Receiver-SiRF-Star-IV-/231066341387?pt=AU_GPS_Accessories&hash=item35cca0900b
Sirf 3 chip units are only $40 now posted.
www.ebay.com.au/itm/NEW-Globalsat-BU-353-BU353-USB-GPS-Receiver-Laptop-NB-/230620688565?pt=AU_Electronics_GPS&hash=item35b21070b5
The Sirf 4 chip puck can just sit on your chart table somewhere. It can access satellites instantly through steel roofs and structures where ordinary receivers like Garmin have no chance.
Select to expand quoteRamona said..
The Sirf 4 chip puck can just sit on your chart table somewhere. It can access satellites instantly through steel roofs and structures where ordinary receivers like Garmin have no chance.
Are you seriously saying that one of these units can get a signal through a steel coach roof of a steel yacht??
Select to expand quotecisco said..Ramona said..
The Sirf 4 chip puck can just sit on your chart table somewhere. It can access satellites instantly through steel roofs and structures where ordinary receivers like Garmin have no chance.
Are you seriously saying that one of these units can get a signal through a steel coach roof of a steel yacht??
Works perfectly through my steel roof at home. Its highly unlikely I would ever want one to recieve through a steel deck on a yacht!
Select to expand quoteRamona said..
Its highly unlikely I would ever want one to recieve through a steel deck on a yacht!
No prizes for guessing why that would be so.
So at least if mounted ON a steel coach roof, it would be unlikely affected by mast, rigging etc.
Tech stuff just gets better and cheaper all the time.
Select to expand quoteRamona said..
Works perfectly through my steel roof at home. Its highly unlikely I would ever want one to recieve through a steel deck on a yacht!
Yeah but hang on Ramona, you live in a double story house so your steel roof is closer to the satellites 
The old BU353 with the Sirf 3 chip used to work fairly well sitting on the side of the chart table. Directly above where the Gps puck resides are two 2 speed winches and a few jammers so apart from the mast and boom there is plenty of metal above. They are made to go in the roofs of steel cars, that's why they have magnetic bases.
I have a eeepc901 and gps puck setup as my chart plotter.
Have been using it for about 5 years and always works well.
The open cpn software and my "russian" cmap charts are adequate and seem very accurate the places i have used them , mainly port phillip , westernport bays and a trip down to refuge cove. which we entered for the first time at night using this setup !
I have used both a usb connected puck and a bluetooth puck ($20 on ebay) my only irritation is that sometimes the way open cpn handles the serial port selection can be a bit annoying and inflexible.
This could be complicated on my setup as i use a virtual serial port emulator to allow me to use the AIS module in open cpn.
Not sure if any of you have tried this but i have it setup and it works well
the basics are
if you have a vhf reciever (mine is a uniden scanner)
you can modify its output as explained here
www.discriminator.nl/index-en.html
connect the output to the soundcard on the pc
www.discriminator.nl/ais/index-en.html
install the demodulation software monitor
groups.yahoo.com/neo/groups/aismon/conversations/topics
install the virtual serial port emulator
www.eterlogic.com/Products.VSPE.htmlhttp://download.cnet.com/Free-Virtual-Serial-Ports-Emulator/3000-2206_4-10836189.html
tune the reciever to the ais frequencies
configure open cpn to run the ais module
then you should have a chartplotter with ais
its quite a few years since i set mine up but have found that it is very reliable
To clarify, I went with the Globalsat MR 350 because it is (a) waterproof and (b) transmits serially (not USB). The former means I can mount it anywehre to maximise satellite coverage and the latter means I'm not tied to using it with a laptop; i.e, it can be used it any serial device that speaks NMEA 0183.
Point taken about SIRF IV being superior to SIRF III.
Must try those "Russian" cmap charts in my area :-)
