Garmin Live Track for safety reasons, will it work with no data by using my phone instead.

Without mobile data there will be no LiveTrack. The data of your activity needs to be transmitted somehow, and without data roaming, there is no way to do it. Wifi in the hotel won't help you, unless you just want to send the friend your position in the hotel before leaving (or after the arrival).

Thank you trux, I was hoping gps would allow it to happen. Ok, thats a bother then, I'll have to think of something else.

9440077 said:

I was hoping gps would allow it to happen

GPS is a downlink only. The watch cannot send anything to the GPS satellites. It is a one-way communication.

You could get a pay-as-you-go data SIM from a Swiss network operator when you get to Switzerland and use that in your phone in place of the SIM from your usual provider during your activities.

If you have a dual SIM phone you can put the Swiss SIM in the second SIM slot and set it for data connections.

what a great idea, yes thank you

If you are only going to switzerland the best option is to get a local sim card pre paid one. However, if you plan to visit several countries maybe look in to Vodafone red roaming, for a fixed fee you get the roaming.

Basically in Europe all roaming between countries was abolished except UK (due to brexit) and switzerland. A word of caution, in Europe it's easy to be at roaming near the countries borders.

There is also another problem - in some remote areas of the Alps, especially in valleys shielded by mountains from the GSM antennas, there may be a problem with the signal reception. I'd recommend checking the coverage beforehand for example at 3G / 4G / 5G coverage in Switzerland - nPerf.com to avoid an unpleasant surprise. And in deep valleys or in the proximity of steep mountains, there may be also a problem with the  GPS signal reception as well.