As I remember, there was a stink kicked up by lifeboatmen sometime around 1965, because of the perceived unseaworthiness of the lifeboats they manned. I think it was because they were not self-righting. Several crews refused to use the 'proper' lifeboats but turned out in their private MFVs.

MFV = motor fisheries vessel, a dated-looking but apparently remarkably good design.   Are they still around in Scotland and the north of England?