Every time you add a new payment method, it is saved and listed with the others you may have previously added. In order to view this list, click on the Billing option at the My Account Section (if you have never added a payment method you will see a respective message instead).
The first payment method you add to MarineTraffic will be your default one. This means that in case of a future purchase it will be automatically used to enable you to perform the transaction without you having to re-enter the respective information. However, it is possible to change your default payment method easily.
For example, suppose you wanted to set the following payment method as your default one:
You should start by clicking on the "Make default" link at the upper left corner. The following message would pop-up to inform you that all upcoming fee charges will be made using this payment method from now on.
Click on the "OK" button and your default payment method will change. The frame will be highlighted in blue to directly denote that this will be your new default payment method, as shown in the next picture.
Note that you can delete a payment method by simply clicking on the "x" button located at the top right corner. Select OK at the confirmation message that will pop-up and this payment method will be deleted.