OK, I'm impressed. A courier just delivered a brand new replacement GPS unit.
Note this UK repair number: 02380 524000
After just under a year, the USB connector was corroding and I was trying to get the unit repaired. I was alarmed when Garmin told me a unit sold as waterproof was only water-resistant. This provoked an exchange of e-mails.
My conclusion is the waterproof standard it satisfies sounds good to the layman, but means little in practical terms.
So in future, I will treat this unit as water resistant unit, not waterproof.
Now - how on earth do I get my BlueCharts installed on this when they're unlocked with a different key?
But contrast Garmin's approach with that of Field & Trek? Incidentally, a nice offer from AlpKit to help with the repair has just arrived - thanks Jim.