Here are some images of the arrangement we have for our Red Box. There is
an external antenna and 6m length of cable. A temporary mount for the
external antenna is fitted to the top bar of the spray hood (note close
proximity of the boom and the stowed preventer stay!). The external antenna
is only fitted to make/receive data transmissions. The cable runs across
the top bar of the spray hood, down the side and through an open hatch into
the aft cabin (standfast the Damage Control Officer). Down below the phone
is on the bunk. The Red Box is on the shelf on top of the wardrobe with a
handy 12V socket nearby. My rugged laptop on the chart table is connected
to the Red Box by wi-fi..
When rigged it has worked very well.
Obvious issues are: Safe rigging in rough weather, especially screwing the
antenna onto the mount one-handed while holding on with the other; Damage by
boom; Running a cable through an open hatch, albeit one under the spray
hood; Waterproof integrity of cable connector when the antenna is removed
(so we de-rig the cable as well); Time & effort needed to rig/de-rig when
one is tired and weary.