Transferring to Hawaii? Under 21? Better start kicking that smoking habit now.

The state last week became the first in the nation to ban the purchase, use or possession of tobacco products and electronic cigarettes by people under 21 years of age. The new law goes into effect Jan. 1 and comes with a built-in punishment scale: $10 for the first offense, $50 or community service for subsequent violations.

About 116,000 service members and dependents are stationed in Hawaii, according to March figures from the Defense Department. The figures do not include Coast Guard personnel.

The demographics for that report are not broken down by age, but the results of a 2011 DoD health-related behaviors survey were:

More than 1 in 4 active-duty service members ages 18-20 are active smokers.

The Marine Corps has the most young smokers by percentage at 31.6 percent.

The Army, which has more than 22,000 soldiers on Hawaii, comes in second at 30.8 percent, followed by the Navy (25.5 percent), Coast Guard (18.2 percent) and Air Force (17.5 percent).

DoD estimates that it spends $1.6 billion a year on tobacco-related medical costs.

Hawaii County, which encompasses the state's largest island, already has a similar ban. But it doesn't cover service members at Schofield Barracks, Joint Base Pearl Harbor-Hickam or Marine Corps Base Hawaii-Kaneohe Bay, all located on Oahu.

Service members were brought into the debate by those opposed to the ban; some of them took issue with a 20-year-old combat vet, for example, being denied a cigarette.