Trails are usually more than wide enough to accompany two skiers (a
fast one and yourself) without the faster one having to call out a
warning each time. (...)

The fact is that some slower skiers do get startled by faster skiers
who whizz by them because from their very subjective point of view the
trail is not wide enough and/or the faster skier passes too close for
comfort.
Etiquettewise this is just as importnat as their objective safety - and
the relevant questions are whether we should startle them or not and,
if not, how could we best avoid causing them any displeasantness.


IMHO there are two rules: 1) Do not appear like a bolt out of the blue;
make some noise (kick loudly, cough, whistle, whatever) *well before
you=B4re at his/her tail* and 2a) Switch tracks or hop into the skating
lane/ *in good time* or 2b) make your skating movement narrower(so that
it=B4s immediately obvious to the slower skier than there=B4s no need for
him to jump anywhere to avoid a collision or to escape your fury) .
There=B4s usually no need to issue any explicit warning.

However, if the passee moves aside it=B4s polite to thank (and if you
have the time, to add "It=B4s the faster skier who moves aside,
though!").


Anders