Whether it's a freediving specific version or a scuba model with an apnea mode, a computer is an essential element of serious freediving. Beyond tracking depth, dive time and surface time, look for a model that provides the level of detail, flexibility or operating simplicity that you want.

In dive mode, the Smart Apnea displays depth, dive time, water temp. and descent and ascent speeds. On the surface, it shows recovery time to safely plan your next dive. Programmable alarms include depth, time, recovery and speed, and the segmented LCD display is easy to read at depth or on the surface.

The F.10 displays info including depth, dive time and surface-recovery time, and allows the user to customize audible and visual alarms and prompts, including elapsed dive time and depth. The onboard log records data from up to 99 dives.

The OMR-1's dive display activates when it hits water, showing depth, elapsed dive time and water temperature. The size of a compact watch, it has four-button control and a built-in log that records depth, dive time and water temp from the last 200 dives.

In apnea mode, the Mantis has a long menu of programmable settings, including diver-customized surface internal factor calculations with a display that shows a "no dive" symbol until it sounds an audible alarm when the required recovery time has elapsed. The Mantis also has a total depth counter with an alarm that can be set in 20-meter increments from 100 to 1,000 meters.

The Amphos' freedive mode displays elapsed dive time, depth and water temperature, with max depth and a countdown timer on alternate screens. It displays surface time after the dive, and has multiple programmable audible and visual alarms, including depth, elapsed dive time and countdown timer.

A noseclip frees up your hand when you need a nose pinch for quick equalization. Omersub's is made of an ultralight composite and has rubbery nose pads.

Made of lightweight aluminum, this clip has soft, felt-like material on the nose pads for a secure, comfortable grip on your mask's nose pocket.