Looking for an alternative to installing an on-deck chartplotter? PS reader Bill Boyeson came up with a creative way to use his laptop for navigation, rather than a multi-function display in the cockpit of his J/42. The Kirkland, Wash., sailor designed an enclosure that protects the setup from the elements and that can be easily removed and stowed belowdecks when not in use. Here are the details that Boyeson shared with Practical Sailor.
In lieu of an expensive chartplotter, I use a touchscreen laptop with Coastal Explorer software, along with a separate AIS receiver, which is hidden behind the laptop. The whole assembly can be removed from the boat, and I only need to plug in 12-volt power to make the setup operational.
The GPS sensor and the AIS antenna are part of the enclosure, which is protected from the elements in most conditions.
Before I built the enclosure, I considered buying a dedicated chartplotter, but I quickly realized that it was going to require exposed, above-deck cables for the power, the AIS signal, and the GPS signal. Also, I would need to figure out how to route all these cables to other locations on the boat. I wanted a nice, clean installation, and since I already had the laptop and the charting program, the all-in-one enclosure seemed like a more sensible and less expensive solution.
The enclosure is made from half- and quarter-inch StarBoard (painted grey) and small stainless screws. Using a table saw, it was easy to cut and notch the pieces for assembly; it can easily be cut and assembled in one day.
The enclosure sits on a saddle that straddles the sheets led to the cockpit. Each leg is an inverted T shape, so that it can be screwed into the cabintop in four places. A single quarter-inch bolt connects the box to the saddle and allows the box to swivel.
If you build your own, be sure the box is wide enough that the laptop can be turned on while its in the box and to allow USB accessories to be plugged in. There also should be lip on the boxs top to keep the computer from falling forward.