It is important that pool operators do not over load a pool with bathers. It makes it difficult for lifeguards to spot people in trouble and it also has a negative impact in the quality of the pool water.

Pool operators need to establish two different types of bather load:

- Instantaneous bather load
- Total daily bather load

In order to calculate the **instantaneous** bather load, the following formulae should be used:

- For water that is under 1.0m deep, each swimmer should have 2.2m2 of surface area each
- For water that is 1.0 – 1.5m deep, each swimmer should have 2.7m2 of surface area each
- For water that is over 1.5m deep, each swimmer should have 4m2 of surface area each

As an example, for a swimming pool that is 25m x 12m with a shallow end depth of 0.9m and a deep end depth of 1.9m.

Divide the pool up into zones according to the depths given below:

- Less than 1.0 metre
- Between 1.0 – 1.5 metres
- More than 1.5 metres

Calculate the square metres of each zone by multiplying the length of the zone by the width of the zone.

Divide the square metres of each zone by the following figures:

- Less than 1.0 metre: divide by 2.2
- Between 1.0 – 1.5 metres: divide by 2.7
- More than 1.5 metres: divide by 4.0

Add the figures for each zone together to get an overall maximum instantaneous bathing load.

Example:

- 108m2 divided by 2.2 = 49 (when rounded down)
- 108m2 divided by 2.7 = 40 (when rounded down)
- 84m2 divided by 4.0 = 21 (when rounded down)

49 + 40 + 21 = 110 would be the maximum instantaneous bathing load.