Get fit to Apply beforehand. Make sure you can pass the PJFT on a treadmill. Make sure you have your birth certificate, a valid passport (ideally at least 12 months to run), your NI number and your NHS number when you submit your online application to join the Royal Marines. Use the online practice Naval Service Recruit Test. Prepare for the Selection Interview - know your Corps History and training pipeline. If you need to declare any medical conditions on the medical questionnaire, you can save a lot of time by obtaining copies of your medical records relating specifically to the declared conditions and submit them at the same time as your Med Questionnaire and completed eye test forms. This can save weeks or months. Make sure you fully complete your online security clearance application at the earliest opportunity, ideally after the selection interview otherwise, if you leave it until after passing PRMC, you will add a couple of months (or more) to your wait for entry.