[bobetter]

In Europe, and I think much of the rest of the world because of the general acceptance of British Admiralty charts and sailing directions, less that 1NM is usually in cables. A cable being 0.1NM.
So I'd go with what I'm used to - decimal miles.

Ron

I disagree. In any UK Local Notice to Mariners, distances of less than 1knm are referenced to meters. While I've only sailed in European waters once (from The Netherlands to Newport, RI via France, Spain and The Azores) any VHF conversation I had on that trip referenced meters. I've also done quite a bit of sailing in the Caribbean where if you used the term "Cable", you'd soon have a pile of electrical wire sitting in the cockpit. : > )
While I've not seen this in fact, I would suspect that in the UK as in the US any security zones around high risk vessels (navy, LNG carriers, etc.) are also referenced to meters. Indeed, MacENC does have the ability to measure meters or yards. Check out the preferences panel.

I think that perhaps this discussion has run into an area affected by the transition from paper chart navigation to electronic navigation. In addition to being able to perform all the traditional navigational tasks expected of paper charts (hence distances over 1 knm being given as 1.xx knm), electronic navigation gives us the ability to measure with much more resolution distances RIGHT ON THE CHART between, for example, us and other vessels or us and navaids without using other range/bearing measurement tools. If I am in the vicinity of another vessel that has a 300 yard security zone around it, I would much rather be able to measure that 300 yards rather than see 0.18 knm. Evidently, the various authorities feel the same way since they use yards/meters.