The evening's rising tide strands two children and the adults who waded out to rescue them.
The emergency services were phoned at just after 6.30pm on Thursday (18 May).
Two children had became stranded on Houmet Besne, the islet just to the east of Bordeaux harbour.
The two adults who tried to get them off also became stranded, and the currents at Bordeaux are notoriously strong.
St Peter Port's inshore lifeboat was launched at 6.30pm and had put the four safely ashore at Bordeaux pier by 7.05pm.
Last week, the RNLI announced that the vessel had become a permanent addition to its life-saving assets in Guernsey.

Police share update on suspected murder in Alderney
Suspected murder in Alderney
Blank canvas for enhanced Alderney ferry services
Annual Navy commemoration service in Guernsey
Information session ahead of Guernsey parish elections
Guernsey team conquer Kilimanjaro in memory of Rose Haysom
Work on broken sewer off Guernsey's east coast set to begin
Ministers meet to discuss Channel Islands connectivity