Please note that your Cobra marine radio has 3 different channel maps:

USA Channel Map – this channel map provides access to channels commonly used in the USA.

Canadian Channel Map – this channel map provides access to channels commonly used in Canada.

International Channel Map – this channel map provides access to channels commonly used in international waters.

If you cannot access a particular channel then most likely you need to change the channel map.  Please refer to the owners manual on how to change the channel map.