You have to go out, but you do not have to come back
This is from the Coast Guard Historical Office - it should help to put things in to perspective on this:
A letter to the editor of the old Coast Guard Magazine written by CBM Clarence P. Brady, USCG (Ret.) which was published in the March 1954 (page 2) issue, states that the first person to make this remark was Patrick Etheridge. Brady knew him when both were stationed at the Cape Hatteras LSS. Brady tells the story as follows:
"A ship was stranded off Cape Hatteras on the Diamond Shoals and one of the life saving crew reported the fact that this ship had run ashore on the dangerous shoals. The old skipper gave the command to man the lifeboat and one of the men shouted out that we might make it out to the wreck but we would never make it back. The old skipper looked around and said, 'The Blue Book says we've got to go out and it doesn't say a damn thing about having to come back.'"
Etheridge was not exaggerating. The Regulations of the Life-Saving Service of 1899, Article VI "Action at Wrecks," section 252, page 58, state that:
"In attempting a rescue the keeper will select either the boat, breeches buoy, or life car, as in his judgement is best suited to effectively cope with the existing conditions. If the device first selected fails after such trial as satisfies him that no further attempt with it is feasible, he will resort to one of the others, and if that fails, then to the remaining one, and he will not desist from his efforts until by actual trial the impossibility of effecting a rescue is demonstrated. The statement of the keeper that he did not try to use the boat because the sea or surf was too heavy will not be accepted unless attempts to launch it were actually made and failed [underlining added], or unless the conformation of the coast--as bluffs, precipitous banks, etc.--is such as to unquestionable preclude the use of a boat."
This section of the Regulations remained in force after the creation of the Coast Guard in 1915. The new Instructions for United States Coast Guard Stations, 1934 edition, copied Section 252 word for word as it appeared in 1899.