The colloquial American-English phrase to have both oars in the water and variants mean to be mentally stable, to be sane.
This phrase to have both oars in the water refers to the necessity of dipping both the oars into the water to keep a rowing boat steady and steer it in a straight line—as illustrated by the following paragraph from The Franklin Evening Star (Franklin, Indiana) of Saturday 30th April 1927:
Sir Walter Scott* was being rowed across the lake one day by a boatman, when he chanced to notice that the oars were lettered respectively, “Faith” and “Works.” He asked the old man why they were marked thus. Without a word the old man began rowing with the oar marked “Faith,” and of course the boat turned in a circle, and then with the one marked “Works” with the same result. Dipping both oars into the water again, as the boat shot forward he remarked, “Faith and works must pull together.”
* Walter Scott (1771-1832) was a Scottish novelist and poet.
I have found an early occurrence of the metaphor, denoting stability, in the following passage from Will Chamberlain Boosts Candidacy Of Tom Berry For Demo Nomination, published in the Evening Huronite (Huron, South Dakota) of Monday 18th April 1932:
(Editor’s Note: Will Chamberlain, well known South Dakota poet and author wrote the following intimate sketch of Tom Berry, democratic candidate for Governor. Chamberlain, a Yankton man, became acquainted with Berry while he served in the state legislature with him.)
Yankton, April 18.—[…]
Mr. and Mrs. Berry have a pleasant ranch place, they and their four children […].
Mr. Berry engages in such farming as goes well with his main purpose—cattle. He looks to alfalfa as a crop the ranchman should not neglect. He has been hit, the same as about everybody else, these last years, but he studies the situation with characteristic candor and foresight and is keeping both oars in the water and the boat steady.
The earliest occurrence of the phrase to have both oars in the water that I have found is from Predator control is not a cure at all, by John Russell, Wildlife Biologist, published in the National Road Traveler (Cambridge City, Indiana) of Wednesday 30th November 1977:
“Why don’t those idiots in the Conservation Department listen to us? If you ask me, those boys don’t have both oars in the water!”
So spoke the man who said the answer to dwindling game population lies within the realm of predator control. “It’s simple,” he said, “if you kill all foxes, hawks, owls, house cats, etc., there will be a covey of quail on every door step.”
The second-earliest occurrence of the phrase to have both oars in the water that I have found is from a letter to the Editor, by James Hull, published in The Post-Star (Glens Falls, New York) of Monday 25th September 1978:
Who is kidding whom?
In light of the escape of Robert Garrow (who I guess grew wings and flew out) from Fishkill, maybe the people, mainly the taxpayers of New York, will take a good hard look come election time at some of our state officials, and take an even longer look at the state’s correctional and judicial systems.
Sometimes I think the bad guys and their lawyers are smarter than the good guys and the judges.
Of course, Garrow’s escape will be blamed on the poor correctional officers who “let” him escape. Not on the top people who apparently couldn’t tell if Garrow could walk or not. I tell you it certainly is reassuring to know that these top medical people are the same ones to judge if a person is mentally capable to stand trial. To be quite frank, if these top medical experts can’t tell if a man is able to walk or not, how can they tell if a guy has “both oars” in the water? Amazing isn’t it.
The variant only one oar in the water occurs in the following passage from Bredehoft Cooking Up New Batch of Zaniness, by Randy Brown, Sports Editor, published in The Wichita Eagle (Wichita, Kansas) of Friday 27th April 1979:
Every now and then, one must check into the wacko world of Wichita State’s Ted Bredehoft. It’s the only way to be sure you know what exotic new bit of zaniness he might be up to. Or down to, his detractors would say.
Believe it or not, Bredehoft, a most unusual athletic director, sometimes keeps his craziest ideas to himself. He was hatching one of those yesterday.
Now some think Bredehoft is not playing with a full deck. You know. Porch light is out. A few bricks shy of a full load. Only one oar in the water.