This method allows you to determine your underwater position by using diving instruments such as a compass and gauges.

● Water Depth and Temperature

When the bottom topography is simple, shallower water generally indicates you are closer to shore, while increasing depth usually means you are moving offshore. Always confirm your depth using a depth gauge.

Water temperature may change due to river inflow, spring water, or variations in depth.

● Compass Bearing

Use a compass to monitor and maintain your heading. Accurate bearing control is essential for precise navigation.

● Underwater Travel Time

If you swim at a consistent speed, the distance traveled within a specific time period will remain relatively constant. By tracking time, you can estimate the distance covered.

● Submersible Pressure Gauge (SPG)

At a constant depth, air consumption is approximately proportional to distance traveled. On an out-and-back dive at similar depths, air usage for the outbound and return segments is often similar.

It is helpful to know your approximate air consumption rate per unit of distance in advance.

● Fin Kick Cycles

You can estimate distance by counting fin kicks. Measure the approximate distance covered per kick cycle in advance for greater accuracy.