The time that you spend underwater is calculated by dive computers. They monitor the depth and time you are underwater, then calculate a safe ascent time. Fortunately, over time the size of dive computers have decreased to the point where a dive computer can be fitted onto a wristwatch, allowing you to wear dive watches throughout the day during and outside your diving sessions.At Ozzy Nautilus you will find core dive computer watch brands, such as Garmin, Oceanic and Shearwater at great prices!Extra features such as heart rate monitors or electronic compasses are also featured on dive computers. They can also be used for air or nitrox.In current times dive computers have a wide variety of options: they can be set for diving with multiple different gases, have screens with bright modern colours, allow different ranges of conservation and furthermore, users can now choose the appropriate algorithm that suits the type of dive they are doing. As technology advances, dive computers are becoming more and more interlinked with the everyday life of a diver!Some divers opt for an air integrated dive computer. Wireless air integration works via something called a sender unit (otherwise known as a transmitter or POD). It is then slotted into a regulator’s first stage high-pressure port. Upon connection it sends cylinder pressure data to dive computers, displaying cylinder pressure and saving them to the watch's dive logs. This information can also be used to calculate air-time remaining values.Bluetooth connectivity is another recent development, this now removes the need to connect the dive computer to a PC with a physical cable. Smart devices can now wirelessly connect to dive computers that are compatible. This dive data can then be downloaded and shared onto dive profiles or social media.If you own a dive watch that is outdated it is highly recommended that you upgrade it for your safety.