Standard Horizon Plotter

[Scratch]

I was wondering if anyone has ever set up a CP180i inside a cabin. I realize that SH makes an external antenna version but I have the 180i already and if it will not be affected by a little fiberglass and plywood I would just assume use the one I have. Thanks

[slacker]

I cant speak for the SH but our Garmin GPS 12 works fine down below shooting through the deck. This particular model is about 8 years old so newer units should be better. We are thinking of upgrading to one of the new SH plotters and would love to know how well it works down below.

Mike

[jemsea]

I have the SH 300i and have set it up so it mounts in the cockpit and in the cabin. It acquires a GPS fix quickly in both locations.

I use the inside mount for planning in the evenings. The 300i comes with two cables but just one is needed for operation so why not have dual mounts?

[dacust]

I would always go with an external antenna.

First, the good news:

A GPS signal will travel through fiberglass and canvas just fine. A plywood or cored deck may also let it through, but may not, depending on the thickness and/or composition.

Also, the signals are stronger than they were a few years ago. The signal may bounce around, coming in through windows, etc. A few years ago my Garmin GPS III+ would not pick up a signal inside at all. But now it gets a lock just fine in the middle of my home office. Don't know if it's coming through the roof or the windows, or maybe both.

Now the caveat:

When mounting below decks, where you will notice the difference is when the weather is bad or sunspots are active or ... In those conditions, the signal gets marginal. The addition of decks may well make the difference in receiving or not.

I would mount an external antenna if you really want to maximize your reception in marginal conditions.

-dan