Very nice website indeed. The booking engine is fabulous I have only a couple of comments that are perhaps nit-picky but would perhaps bring this site from outstanding to over the top.
First, when I land on the splash page as a new visitor, I spend some time on the site before I figure out that your company specializes in package holidays (airfare, hotel, set departures and durations). Perhaps a few words to the effect of what your company is offering... up front and to the point.
Your heading "Our Gambia Holidays" maybe could be something more enticing like "Experience Gambia". Minor semantics perhaps but I think more clickable and more to the point of the category (or maybe "Your Holiday in Gambia"??).
"New to The Gambia Experience?"... how about "Why The Gambia Experience?"
On a functional navigation note, your hotel description page should probably include a "Book this Hotel" button at top or bottom (or both) of description. This would give direct link to "Prices and Availability" and the "Book" button that you really want to help people find.
If striving for perfection, your booking function "Extras" would also give people the opportunity to prebook excursion trips. I see how you handle excursions and I appreciate there are probably very good reasons for handling your excursions as book on arrival.
Nice niche; nice site; difficult to find much to say. Your SERPis already doing very well indeed, keep an eye on those keywords, maybe need a couple of tweaks. For example check your title and density and maybe you can quickly get 1st page Gambia Hotels (I use Google.com maybe you are already where you want to be in the UK).
Also, where is your link partner area? I would be interested in doing some reciprocal linking, if you are interested you can contact me through any of my sites via contact form. We about to begin promoting a travel site design niche for our business and I am grateful to stumble across one of the few very well designed travel operator sites (
Travel Website Design, Travel Website Development, Travel & Tour Website Designers).