incident dectection shall send sms wihtout phone connected to internet

That would require a cellular connection from the watch directly, which has some technical challenges like power usage and a SIM card in the watch. However it may be a good idea for a new type of watches, feel free to share it here: https://www.garmin.com/en-US/forms/ideas/

I too would like to have livetrack and be able to trigger an alert from my watch, without having to take a phone along. Over the years I've (water) damaged several phones due to various outdoor mishaps, and tried alternatives like handheld amateur radio equipment and low power "internet-of-things" data transmitters, but those were bulkier and less convenient than a phone.

Also, the idea of being trackable even _without_ a phone does not appeal to me.

More importantly, 3G/4G/5G based solutions are not ideal for areas without adequate cellular coverage, for that a satellite communications-based option or a personal locator beacon is a better choice.

I'm still looking for a solution to have live track+alerting that works without cellular coverage and without expensive activation and subscription fees, so if anyone has experience with these things, please share!

No, this is not what I suggest. the watch connected to the phone, and the phone just sends sms to the urgency contact in case of urgency.

And that is how it works: sms don't need a data connection.

How would this work if the phone does not have a cellular connection?

It does not work without a cellular connection, but he is specifically talking about a data, Internet, connection, which is a subset of the cellular connection. You can make voice calls or send SMS messages even with your data connection switched off, but you can't browse the Web or sens WhatsApp messages. :)

No I meant the 4g, (data) not activated. If the phone is not connected to internet it does not send the sms.

Can you make a test? Turn off wifi and data on your phone and trigger an alert. On mine it did not work. Connected to wifi ok

Exactly what I meant :-)

This is weird because in remote areas where you might need this function, the connection is often so poor, that internet doesn't work whereas SMS is still possible.

The bluetooth connection between watch and phone must be on and connected: are you sure you had only shut off wifi, data connection (3G, 4G), and that the phone was connected to a cellular network, and to the watch with bluetooth?