I am a military mom and I know that just about any ship, base or chaplain will be able to connect you with a service member who would appreciate a pen pal. My son was on several different ships and each one had a chaplain. I would imagine that you could get send mail to the ship addressed to the attention of the chaplain and they would be able to connect you with someone. A couple of ship names I am familiar with are the USS Bataan, USS Blueridge and the USS George Washington. These are a few of the ships that my Marine son was on board during his years of service. God bless you for wanting to befriend them!'