optional, single

—

With <minimumvisibility> the minimum visibility to be expected at the dive spot described is put into bracksts. The value is given in metres as a real number.

<sitedata>

—

<averagevisibility>, <maximumvisibility>, <sitedata>

(see also <sitedata>)

<!-- minimum visibility to be expected is 30 centimetres -->
<minimumvisibility>0.3</minimumvisibility>