the 10m band typically has a reach like line of sight. it is also very likely that many rescuers will broadcast simultaneously so a wide reach (like > 20 kms/miles) is actually not good
Fortunately, the 10m band these days has a reach of up to 11000km due to the solar activity. You are quite right that during LOS conditions it’s limited to the elevation of the antenna.
Its relatively small antenna needed (5m dipole) and can be used to access some distances, just not ones that might be in the same country as origin because of the skip dead zone from the ionospheric refraction angle. Which depending how it might be used, could be useful.
The general rule of thumb is to check the MUF Rating at the time of day collected from ionosondes such as that on https://prop.kc2g.com/
I'm not trained in emergency ham operations, but I assume they know what they are doing. They're a community which is enthusiastic about their utility in crisis, I mean this in a good way.
Some localities they are useful and some they get in the way. Emergency ham operation is not always required or welcome. It’s very specific to certain localities.
Fortunately, the 10m band these days has a reach of up to 11000km due to the solar activity. You are quite right that during LOS conditions it’s limited to the elevation of the antenna.
Its relatively small antenna needed (5m dipole) and can be used to access some distances, just not ones that might be in the same country as origin because of the skip dead zone from the ionospheric refraction angle. Which depending how it might be used, could be useful.
The general rule of thumb is to check the MUF Rating at the time of day collected from ionosondes such as that on https://prop.kc2g.com/