Timer as Chain Counter

[Dockhead]

I'm just back from a month of cruising, during which we spent most nights at anchor. Some of them in North Brittany and the Channel Islands, where the tidal range can be huge -- up to 14 meters. When you're dealing with a huge tidal range, it is particularly important to put out the right amount of chain.

Somewhere low on my wish list for a long time has been to install a proper chain counter like the Lewmar one. But this is expensive and a hassle, because you have to install a little magnet in the gypsy and a bunch of wiring.

Why couldn't we measure the amount of chain out by simply measuring the time during which the windlass is active in the "down" direction? I know this wouldn't be accurate in all conditions, because when running "up", the length of chain per second of operation will vary according to load. But going down, it must be pretty consistent, and this is mostly all we care about anyway.

All it would take would be some kind of intermittent timer which counts second when energized on "down" (and ideally, subtracts seconds when energized on "up"). Then calculate how many meters are in one second, print up a conversion table, laminate it, post it next to the timer. Wouldn't that be a great, simple, cheap solution to the problem? Anyone thought of this? Anyone know a suitable electronic timer?

[mrm]

When going down load will also change, although not as much as going up, so possibly this could be ignored, but... the timer would have to be wired in to windlass steering somehow too, so the wiring issue remains, is only different.

Why not install that magnet and a reed relay on a capstan and combine it with a simple mechanical pulse counter? Total cost in parts probably below $10. The counter would not even have to be resettable, nor would it need to be able to count in both directions. Interpretation is easy enough with wetware

A quick search turns up these:
For Sale: Impulse Counters
Pulse Counters - Counting Technology - Products - Kübler Group

Reed relays and magnets can be found cheaply in home security shops, for example.