There are a number of different radios in use, currently they are all PMR446; ie. they use the 446MHz public licence free frequency. The operating instructions for eachtype are in the links below, click to view.
[These are not due to come into service until after 31st October 2020]
The Cobra radios float and have good coverage.
Hytera radios are very good proffessional quality radios, they
are waterproof but do NOT float.
These are an earlier PMR446 radio, good quality but are
NOT waterproof and do NOT float.
There are only two of these which were bought as an experiment. They float and are waterproof but the audio volume output is not that loud.