In respect to this, is the GoPro Hero 4 session waterproof without a case?
​No. These cameras are NOT waterproof without a housing. Each of the HERO4 cameras come with the Standard Housing that is capable of withstanding depths of up to 131 feet (40 meters).
Likewise, which GoPro are waterproof? Yes, all current GoPro models (Hero8, Max, Hero7, Hero7, and Hero5) are all waterproof. They don't require an additional case for depths up to 33 feet (10 meters), with the exception of the Max – which is waterproof to just 16 feet (5 meters).
Simply so, how deep can the GoPro Hero 4 session go underwater?
10m
What happened to the GoPro session?
Three years after its introduction, GoPro is killing its Session camera line. It was the first GoPro to have a waterproof/shockproof casing built-in, it dropped the user replaceable battery and it significantly reduced the camera's footprint.