(CNN) -- Smoking and submarines don't mix.
That's the message the U.S. Navy is sending after announcing that smoking will no longer be permitted below decks on its submarines effective December 31.
"This policy was initiated for the health of the sailors who choose not to smoke," said Lt. Commander Mark Jones, spokesman for the Commander Naval Submarine Forces in Norfolk, Virginia. "It is unfair for them to be exposed to the unhealthy side effects of secondhand smoke."
Jones said the submarine force conducted a study in 2009 on nine different submarines covering the four different classes of subs. In that testing, it found nonsmokers were being exposed to the effects of secondhand smoke.
There are 71 submarines in the U.S. Navy and about 13,000sailors on submarine active duty, according to Jones. Of those sailors, recent polling indicates 35 to 40 percent are smokers, he said.
Jones conceded there will likely be complaints. However, he said the Navy has very aggressive smoking cessation programs. There will also be nicotine replacement therapy widely available on the submarines, such as Nicorette gum and nicotine patches.
"We're going to work as hard as we can to make this an easy transition," said Jones.
In the past, smoking had been confined to certain areas on the submarine. Individual submarine commanders will still be allowed to decide if crew members are permitted to smoke on deck.
CNN Radio's Ninette Sosa contributed to this report.