Crab
I thought we had covered this ages ago. The CAA give an exemption to the 500' rule and authority to carry out SAROps and training to lower heights both in VMC and IMC. The civilian operators have laid down SOPs for let-downs to radar contacts/let downs over the sea which have been demonstrated to a CAA Ops Inspector and approved. In some cases they use the same radar that the North Sea operators use routinely to do en-route let-downs to 500' during the day and deck height + 50' for ARAs with a minimum of 200' (day) in IMC down to .75nm
This same radar is more than capable of holding targets to .25nm quite safely for SAR and this is authorised as part of the exemption by the CAA. I know, I have used it in anger to do this. You don't need a dedicated radar operator if the aircraft is capable of reducing the pilots' workload to such an extent that operating the radar is a minor part of the NFP's capacity. Please bear in mind that ops in IMC over the sea, admittedly only to 200', are a common occurrence with a crew of only two pilots over the North Sea.