I have a
chartplotter on the
helm on S/V Sunny Spells as well as the ability to run a
laptop with Software-on-Board, using the
C-Map cartridges from my Navman
Chartplotter (
S.V. Sunny Spells · Navigation Systems).
1. The
laptop draws around 4 to 5 amps. The chartplotter,
autopilot,
AIS,
instruments - in fact everything else - draws less than 2 amps when it's all running. This
single one fact rules out the laptop for primary
navigation.
2. A chartplotter really comes into its own when navigating around obstructions, making landfall at night, or when avoiding traffic using radar or
AIS. The rest of the time you can plot a grid reference on a map. So really, you need it at the
helm. A laptop can't do that unless you want to risk it getting wet.
3. You can now buy a small colour chartplotter with AIS for well under $1000 (Navman), and I'm considering fitting one as backup in the nav station so I can check on it when I'm off-watch at night. Running the laptop is not an option because of the amp-draw.
4. Chartplotters, in my experience, are very reliable. How often does your "Windoze" laptop freeze, crash, restart... I wouldn't bet my life on a laptop!
I always carry a laptop, but it primarily gets used for planning, for writing my blog and keeping in touch via e-mail. It's also good for troubleshooting
NMEA issues...