As you noticed throughout this guide, several of the freediving watches continue to operate when you are 100 feet below water. Given that the average person will only be able to hold their breath for a few minutes underwater, this seems like an unnecessary astronomical amount. However, remember, some dive computers can function for both scuba diving and freediving and this high water-resistance is more beneficial for scuba divers. With that being said, though, there have been divers who have reached 200 meters on a single dive.
It takes practice, not only physical but also mental to handle dives so far below the earth’s surface. If you think it is easy to hold your breath for that long, check out the training regimen that world-famous magician David Blaine went through to try and break the record.