Every child is different in handling these situations. He might surprise, and sadden you just a bit, by handling it beautifully and never missing a beat in his normal life. He might give a dad a bit of a run for his money. Colin was about thar age when his dad would travel we would count sleeps. How many sleeps until daddy came home?? That seemed to make it easier for him to understand. If he isn't in a daycare, I recommend that. Just maybe 2 days a week from 9-1, just get him out there to socialize & realize you will always come back for him. I was a stay at home mom and Colin still had his daycare days and I had mornings to me. It was a nice little break for both of us. Also, are you near a Coast Guard base? You can give a call and ask for a tour for a child... maybe you can get a Coastie to show you a boat or a helo or the uniform and you can explain to your son that mommy wants to do this and how much fun it can be. (You probably couldn't go aboard a boat or something because of liability problems with a little one getting hurt, but you can look from the pier.)
Like any child in America... today "Bye mommy, have a good day" coloring, eating fruit loops & mom thinks my baby doesn't love me, he just let me leave the house without even a sniffle. Tomorrow you are preapred for that and junior throws himself to the floor, grabs your ankles and begs you not to go! Try to figure out babies... they have a will of their own!
Best of luck in your decisions! Welcome aboard. If you have any other questions, let us know, we'll do our best to help.