What is the best way to increase my chance in being selected for a volunteer deployment to Djibouti?

go on HRC web page and volunteer maybe they will select you that way?

Thank you all for the great responses. I will be using the tour of duty site to apply as recommended by my unit. I qualify for the job, however I see there are multiple people that have applied. I am looking for the 'one up'.

There are two ways about this. Log on to the ASK website and check for requisitions or go ask your career counselor. They should also be able to check for available openings.