If you replaced the starter/contacts just 10K ago, it's not likely worn contacts, but perhaps muddy contacts from the crossing? Did you replace the plunger at the same time, or was this a factory-rebuilt unit you installed? If some silt got into the plunger cavity, it may be holding the plunger back from sliding and making contact.
But the clicking may also indicate a bad battery or corroded cables (and or cable ends) which just can't provide the current necessary to start.
If you got in up to the dizzy, you should probably pull the cap and clean it out if not replace it.
The quickest/easiest to check is the cable ends--pull, clean, and retighten them--both battery and starter/body ends. Also check to see if there is a lot of corrosion on the wires themselves (I think you live by seawater which will accelerate this).
If it still won't work, I'd pull the starter and check out the contacts and plunger, then replace the dizzy.