Poole lifeguards in Hitler YouTube video
The RNLI has apologised for what it described as an "offensive" video made by members of its Dorset lifeguard team and posted on the internet.
The video, entitled "Lifeguards Awesome", features Poole lifeguards in uniform on Sandbanks beach.
It includes simulated sex scenes and an impersonation of Adolf Hitler.
The RNLI said it was "extremely dismayed" by the content of the film and had asked for it to be removed from YouTube.
One scene during the nine-minute long video sees a lifeguard offering sex education "advice" which includes references to violence towards women.
Spencer Gammond, head of external communications for the RNLI, said: "The Royal National Lifeboat Institution is extremely dismayed by the offensive content of this video and apologises unreservedly to anyone who has seen it.
"Immediately after this was drawn to our attention we contacted YouTube, and the unknown person who uploaded the video, to demand its removal.
"We are carrying out a thorough investigation and will take disciplinary action against those who have used RNLI resources inappropriately and shown such disregard for the public, our supporters and our charity's good name."
He added that the "shameful behaviour by a very small minority" was not representative of the RNLI's 900 lifeguards.