I'm a BM, it's a pretty sweet job if you get a good station or cutter.
Eric-I got your PM...I'm a officer/pilot so I can't give you as good a perspective on the Enlisted side of the ouse as these other guys, but I think they are on the right track w/ the TACLET/LEDET route. Do be aware that you might end up operating off of Navy ships to do some of the missions. Reserve Port Security Units mig be worth looking into as well.
Also realize that it's VERY competitive to even get a boot camp slot right meow and you'll be waiting for a while.