Back in the mid 90s, the Farnborough Bac 111 was carrying out a trial south of Tenerife which required the aircraft to operate at low altitude over the sea (1000ft or less). When it became time to return to Tenerife South, they requested a 'VFR join with a run and break to land'. The Spanish controllers tried to get them to climb to an IFR level to be vectored for the ILS, but the crew declined. ATC apparently had no conception of visual joins with aircraft of this size, ( I don't know what class of airspace it is there) but eventually allowed it!
Footnote: the break was carried out at 500ft agl, but the pilot misjudged his first approach and had to go round!!