Apple Watch dies when surfing - sometimes???

I need to use Apple Watch cellular for emergencies when away from phone or WiFi but sometimes it drains battery really fast until it is low battery. It can stay at low battery for a long time but when there’s more something drains it. I turned off all the settings that affect data but watch still dies really fast like 75% of the time. I don’t do anything different and for other 25%, watch still has almost full charge after an hour but most of the time it’s on low battery after an hour. Everything is updated and I don’t know what to do. I use Waterspeed app to track my surfing but it stops working most of the time too. Other 25% when battery doesn’t die then it functions fine. How can I depend on my watch to do what it’s suppose to do?