The 20 high-quality HDR images of various underwater places are provided in the most widely used formats:
Light-Probe (Angular Map)
Spherical Map (Latitude-Longitude)
Vertical-Cross

Radiosity - and therefore the use of HDRIs is directly supported in many 3D-applications like Lightwave (version 6.0 and higher), Softimage|XSI, Maya & Mentalray, Pixar RenderMan, Bryce 6, Autodesk VIZ, messiah:render (Arnold), InSight (Integra), 3ds-max & VRay, 3ds-max & Brazil r/s (Splutterfish), 3ds-max & finalRender (Cebas), Cinema4D Version 8.1 and more. For further HDRI-rendering tools options the documentation of the used 3D-program should be consulted.

The HDR images are provided in the following formats:
Light-Probe - 4096x4096, 2048x2048, 512x512 pixel
Spherical Map - 10,000 x 5,000, 6248x3124, 2048x1024 pixel
Vertical-Cross - 4686 x 6248 pixel
Horizontal-Cross - 6248 x 4686 pixel

And each HDR image is provided in the industry standard .HDR. So they are useable in most rendering applications.

Rapidgator