There are two options with regards to applying for a Sea Scout Base course depending on which section you are in.
If you hover over the Applications menu you will see the option for Scout Applications and Girl Guide Applications. This is of course rather self explanatory. If you are a scout you will use the Scout Applications, and if you are a Girl Guide you will use the other.
Payment for both courses however needs to be to the Sea Scout Base. The banking details for which you receive when the application is made.