A bit of direction change here (pun intended)
We've been working with a few Garmin GPS, mainly to see which of the USB powered versions will charge and navigate with our Nuvi USB charging cable. (more here: http://www.advrider.com/forums/showthread.php?t=666156
The Oregon was an obvous choice since it is a USB alternative to the 12V powered 60 or 72 series. We were pleased to find that the Nuvi charging cable would allow the Oregon to charge and navigate when plugged into a USB port just like the Nuvi. However, with the USB cable plugged it left it without the weatherproof protective cover. Not much use on an Adventure bike so we set out to see if we could cobble up some weatherproofing. What we wound up with is butt ugly but it works. Here's how it went.
First we opened the unit up and removed the existing rubber seal part. We then masked off the areas around the seal recess.
Next we applied a thin coat of dielectric grease to act as a mold release.
The cover was replaced and one of our Nuvi Charging cables plugged in. Since this was to be a full weatherproof setup we chose one of our TAPP CAPPed cable so it would be weatherproof at the USB power socket end as well. With the cable in place we squeezed a layer of E6000 adhesive into the recess and allowed it to run up on the cable connector end just a bit.
The small twist tie through the GPS lanyard hole keeps the cable from moving around while the E6000 dries.
It took several hours for the E6000 to dry since we poured it on pretty thick. Once dry we separated the cable from the GPS and let it dry some more. The E6000 shrunk up quite a bit but still fit back into the seal recess nicely. Was the seal ugly? - oh yeah, double ugly even after it was trimmed up a bit.
Did it work? - yup here it is under a spray head with a good blast of water hitting it. We decided to leave the twist tie in place since it will help hold the cable in place against vibration on the bike. There is still room enough to get the lanyard through the holes.
We haven't screwed up the courage to put it in our dunk tank yet but we will after we've used it awhile.
Here's the GPS mounted on our demo KTM (Kiddie Toy Motorcycle) and plugged into one of our TAPP Lite weatherproof USB power ports. Our Garmin 60CSx is on the other side of the bars.
A couple of final thoughts. The Oregon USB connector may be somewhat weatherproof with no more than an application of dielectric grease be we felt that having some kined of water shield around the USB connector would provide a better protection against heavy splash like a deep water crossing. The USB connector doesn't hold the cable in place with sufficient force to withstand typical motorcycle vibration but the lanyard hole provides a handy place to tie the cable down with a twist tie.
All things considered, we still like the 60CSx better since its power cable is inherently waterproof and I'm old fashioned, I like buttons. That's why I still run a Zumo 550 on my touring bike.