“Anyone can steer the ship in calm waters” (also “Anybody can steer the ship in calm waters”) means that maintaining a profitable stock portfolio is easy in calm or prosperous economic times. During economic downturns, special skill is needed to maintain the same level of portfolio performance.
 
The saying as a nautical truth cannot be dated, but the financial use of the saying became frequent during the recession of 2008.
 
Other water-related financial sayings include “Smooth seas make poor sailors,” “A rising tide lifts all boats” and “When the economic tide goes out, you find out who is swimming naked.”
 
   
About.com: Management
Management Tip for Today
By F. John Reh, About.com
L20: Anyone can steer the ship in calm waters. What will set you apart in your career is how you perform during the tough times. Don’t become complacent and relax just because things are going well. Plan ahead for the downturn.
   
Google Books
Ambassador in Chains:
The Life of Bishop Patrick James Byrne (1888-1950) Apostolic Delegate to the Republic of Korea
By Raymond A. Lane
Published by P.J. Kenedy
1955
Pg. 45:
Anybody can steer through calm waters.
   
Google Books
The Organization Woman:
Building a Career—an Inside Report
By Edith L. Highman, Arthur Highman
Published by Human Sciences Press
1985
Pg. 26:
Finally, another executive (obviously a male chauvinist) expounds: “Anyone can steer a ship in calm waters, but can women do it in troubled waters?”
 
8 June 2001, Schenectady (NY) Daily Gazette, “Gloversville weighs option of borrowing” by Jim McGuire, pg. B1:
“Anybody can steer the ship in calm waters,” he said. 
     
Scott Bridwell
Thursday, October 23, 2008
Anyone Can Steer the Ship in Calm Waters
What will set you apart in your career is how you perform during the tough times. Don’t become complacent and relax just because things are going well. Plan ahead for the downturn.
 
Philippine Daily Inquirer
Lean is mean in a recession
By Rene T. Domingo
Philippine Daily Inquirer
First Posted 23:12:00 03/01/2009
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This reminds us of Warren Buffet’s “swimming naked” analogy and the old saying “Anybody can steer a ship in calm waters.”