Very colourful GD47, but wrong era.😉
As far as I know that yellow was only used, very briefly, on the whale-back rescue launches (HSL) very early in WW2. It was dropped pretty damn quick, and replaced with grey, when they started pilot rescue operations in the channel and realised that bright yellow made them easy targets for Luftwaffe Stukas and JU88s.😮💥🔥
The Fireboat /Crash Tender came along about ten years later and was much smaller than the HSL, 46' as opposed to 63'.
Cheers, Doug 😎