Not that long ago, manufactures were very liberal with the term “waterproof” on their products. Some waterproof products could withstand several metres of water, but many products labelled as waterproof only had the minimal amount of water protection. There was really no way for the consumer to know the difference.
Today there is a standardized “Ingress Protection” rating, or IP rating. This IP rating is a two-digit classification that states the amount of protection a device has. The first digit is the rating against solid objects (from fingers to dust) and the second digit is water protection. Most marine equipment is now rated on the IP scale for water.
For example, your GX-2100 is rated IP-x7. Now the first digit is the solid object rating, but since the GX-2100 is not rated for solid object protection, the manufacturer simply use an ‘x’ as a placeholder. The second digit (7) means that the GX-2100 can be immersed up to 1 meter in water for 30 minutes without harming the electronics. It is perfectly safe to be in the rain.