When you find someone willing to give your loads of £ for the Decca please tell me. I've just removed mine but have yet to find someone willing to buy it for me. I try to convince them to the benefits but they just won't understand.
I would find sailing in less than ideal conditions far more taxing without my GPS repeater. I suppose they are made in modern instrument suites - mine is a Stowe one about 10 years old. Displayed course and distance to waypoint can be invaluable when it is inconvenient to leave the tiller.
I use GPS as a reminder of the position of any buoys Im passing close to ,in familiar waters its too easy too get over confident and hitting one in the dark at speed can be disasterous.
As for what toy to fill the old hole how about a waterproof music speaker to keep the helmsman amused on watch.Especially good if you can switch off all the speakers down below at night.Dont forget speakers are strongly magnetic.
Tells me to steer to Port or to Strbrd: sailing for dummies. Especialy usefull for
a) novice crew
b) taking current into accout when crossing from Flushing to Breskens
Otherwise its on SOG, COG, Distance and heading.
It gives me the best of both worlds: a portable GPS (Mag 320) out of the rain, with a large screen.