Advice on Navman 7200?

I have fitted a Navman 7200 class D DSC VHF Radio/ This was new in February this year. I have noticed that the volume on the set appears limited and I have had instances where I could nor readily hear it when at speed or in high winds even with full volume up. My last sets did not have this issue.
1. Is this normal for this set? (have I a faulty one)
2. Is there another setting I am missing to increase volumes apart from volume control?
3. If it is the set can an external speaker be fitted to overcome the levels?

Thank you in advance for replies

Hi, It is not unusual to have a low volume on a "noisier" boat, as most of these radios get sold into the yottie market. The speaker size is quite small and is only 2 watts. The external speaker comes in at 4 watts, so well worth the upgrade.

Also running the internal speaker flat out all the time will cause it to blow quite quickly, then the volume and audio quality will really be bad!!

Geoff.