[ajpershing]

Greetings,
I've been sailing for several years on a daysailor and am moving up to a real cruising sailboat (Bristol 24). The boat was abandoned and I'm working with a yard to restore her. I've been browsing around for electronics and would appreciate our comments on how I plan to set it up.
I have a powerbook and just purchased MacENC (very cool!). I have a handheld GPS (Garmin eTrex) that I plan to use in the cockpit. I envision using MacENC to layout a series of waypoints for the day's sailing and transfer them to the eTrex. Periodically (hourly?) I envision transferring fixes back to MacENC so I can double check and record my progress. Does this make sense? I'm also thinking of permanently mounting a GPS antenna (a Garmin 17-HVS) to continuously update our position on MacENC. Has anyone successfully connected one of these (or the 17-N version it replaced) to a Mac? I would welcome any comments on suggestions (especially, anything I might be overlooking).

Thanks,
Andy

[GPSNavX]

Yes a Garmin GPS 17 will work fine with MacENC. You will have to connect a DB-9 connector to the bare wires and use a Keyspan Adapter or a Multiplexor.

I would ask that you consider the $89.95 BU-353 USB waterproof GPS. It plugs straight into the USB port and has many reception advantages. It works fine near a window or port..

http://www.gpsnavx.com/html/USGlobalSatBU353.html


For your Garmin ETrex you will need Garmins PC interface cable and a Keyspan adapter. You could transfer your track periodically to MacENC, but doing so every hour would be tedious. Much better to have a live GPS connected.

[ajpershing]

Thanks for responding so promptly. Could you give me more info on the USB GPS? My experience with using my eTrex under any kind of cover has been disappointing. Would the unit get a reliable signal mounted inside the cabin, beside or even on top of a nearly vertical port? If not, is the unit rugged enough to be mounted externally?

[fish2live]

I've had one of those little USB GPS units for several years. I have the older BU-303 unit, which I purchased through eBay from a Singaporan mystery dealer for $58. Under the circumstances I wasn't expecting much, but I had already been through the experience of trying to build my own cables for other handheld GPS units, and this thing came with a USB plug.

Boy was I wrong! I'm extremely familiar with GPS units, and I've never seen a marine GPS that acquires as quickly or works with such a limited window. It works on my dashboard no matter which way the car is pointed. We used it to take a tug and barge down Cook Inlet a few months ago by hanging it out the nearest window. We didn't even secure it down. It swung back and forth on its cord for a full day.

I don't know how waterproof these things may be, but for the price it just doesn't matter. I keep mine with me as an emergency backup on a commecial fishing boat. If I needed to navigate a little sailboat, I would use a few wraps of Saran wrap for spray protection in a good exposed location and then take it off when I was done. It may be as waterproof as it is accurate, but there is no reason to leave it behind.

You might get a usable signal by sticking your unit in a window, but I wouldn't do it that way. I wouldn't worry too much about booms or rigging or any other obstruction though. My previous car and tugboat installations have left about 50% of sky view.

The only caveat that I have noticed with my unit is that it seems to continue to operate even when I put my ibook to sleep. I unplug mine if I'm not using the laptop to limit the battery drain. It reacquires so fast that I've never had any issues with plugging and unplugging.

[GPSNavX]

I have used the older TN-200 and BU-303 fine through windows and portholes. The new 20 channel BU-353 works even better. The BU-353
is waterproof.

[Yesdog]

And so, WILL the USB GPX work if placed on the helm station next to the windows, or does good reception require it be placed somewhere outside the boat? The enclosed pilot house on my boat has large windows, but also a roof!

Joy Godsey
m/v Pyxis

[fish2live]

Using several GPS units in my car, I've never had any issue with glass or steel limiting the signal. I naturally stick mine in the window, and I've never tried tossing it in the back seat to see if it would still work. I think I did need to put an older Garmin in the window to get a signal.

There is a bigger issue behind this question, and that is whether you want to add this tiny risk to other tiny risks, ending up one day with a single event leading into some catastrophic domino effect.

Is your GPS a cute toy, or do you get stuck at bad times in tight places in heavy fog? Commercial boats have come to rely on GPS as a last resort, even over-riding radar (in some cases) as the final decision maker. That reliance is based on multiple GPS units. I counted eleven separate GPS antenna heads on an Alaska Marine Highway ferry last summer. I never needed that GPS signal in my car, and though I described in a previous post using a USB unit to navigate a commercial tug and barge, I had a variety of other options available if the laptop and GPS quit working. If you already have other backup options running, then setting your USB unit in the window is likely to be more than enough to enhance the day.

[Yesdog]

My current GPS unit is a Garmin 182C. My next add-on is the GPSNavX (or MacENC, haven't decided) using updated digital NOS and COE digital charts. Other backups... paper charts, compass, sun and stars, first mate, sound and light signals... the usual stuff sailors have relied upon for millennia.

Joy
Pyxis sailing out of Port St. Joe