Comms support was not built into the Nimrod from the outset. Indeed the original comms fit was quite basic with no secure voice. The marine band radios were fitted in the late 70s.
In the Fastnet case, a friend of mine was Captain and they dropped both Lindholme sets and 3 pairs of liferafts. Coincidentally 18Gp had just questioned the need to have liferafts as the existing kit was due for renewal.
Finally in the case of comms relay, the Nimrod provided a reactive capability although a friend of mine was contracted to provide comms relay to the west of Bagdad; they used a tethered balloon at 12-15k.