the RIB drivers on the water requiring individual VHF licenses
I guess in this case that you're referring to the operators' certificate, rather than an equipment licence?
In which case, you're clear. No operators' certificate is required and this should be written in the terms of your licence.
The following wording is directly quoted from my recent Ship Portable licence but should be very similar (if not identical) for your CSR licence.
10 The Licensee must ensure that the radio equipment is used only by persons:
(a) who have been authorised by the Licensee to do so and who have been made aware of, and comply with, the terms of the licence; and
(b) who hold, or are under the direct supervision of a person who holds a relevant Maritime Radio Operator's Certificate of Competence and a valid Authority to Operate.
11 Clause 10 (b) shall not apply to persons using channels M (157.850 MHz) and M2 (161.425 MHz).
12 Notwithstanding the terms of set out in Clause 10 above, in the event of an emergency where there is a risk to life, the radio equipment may be used be any person to summon assistance.