The two clips – one from earlier this month, and the other from November 2019 – each show several people cramped onto a small inflatable before being pulled to safety by lifeboat volunteers.
Both shouts involve the rescue of several migrants, whose nationality is not known, including a baby.
In the November 2019 incident, the majority of those on board are not wearing life jackets, and appear to be dressed only in jeans, trainers and coats.
Some of those rescued appear distressed and barely able to stand, with several wearing sopping wet clothes as they clamber on board the RNLI rescue vessel.
Once pulled to safety, the lifeboat volunteers can be heard trying to reassure the migrants and treating them for sickness and exhaustion
Footage taken in July 2021 of migrants being rescued by the RNLI (RNLI/PA) / PA Media
In the more recent clip, those rescued can be seen prone on the lifeboat deck clutching bottles of water and slumped motionless wrapped in towels.
Mark Dowie, RNLI chief executive, told the PA news agency: “The humanitarian side of this has not really been told properly.
“We wanted to tell this now, our crews are becoming busier and busier with this work.
“It’s important that what they see and what they do is properly appreciated.”