What is the difference between iPhone Samsung S8 and Pixels ? Their water resistance IP 67 vs IP 68. Complete info here
But the last number is what we are interested about.
A 7 rating ensures “ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1m of submersion)” according to the IEC. While a 7 rating guarantees protection for up to 30 minutes.
The Samsung Galaxy S8 received an 8 certification for water resistance, meaning it can be underwater for 30 minutes at depths of up to 1.5m.
A device submerged may suggest it will survive water but there are consequences long term damages that can result from this. /!\ Do not attempt to charge or plug your device if it is still wet for shock and fire prevention.