Hi,
Saw this forum and hope you guys don't mind me hopping on as am from Singapore!
I have had the same issue with a previous Beneteau that had a blue hull, the gel coat just seemed to dry and then chalk up so that it was a white/ghosted blue and not the deep blue it was supposed to be.
I used a product called 'Marine A Glaze' to do three things:-
1 - Remove the UV damage (white chalking)
2 - Polish hull to deep blue shine
3 - Protect
Have to say that this product simply blew me away with how good it was, infact, so good that i have not had to polish the hull since the day that it was put on....that is now nearly 18 months ago! The product is from the UK and in fact comes from the aviation industry, they put it on all the big airliners to protect them from the pollution and keep them protected against UV damage. With being one of the first (of now many) users in our region i have now taken on to represent them locally here, amazing product.
Now, before you think that i am punting - not my intention. I have also been in the industry for the past 20 years and have faced this same question on an annual basis, looking after yachts and their surfaces can be a frustrating and tiresome business - too many of my clients have been frustrated in the past with this sort of problem and one that i did not fully understand until i too owned a yacht! So, i have been on both sides of the fence and happy to say that there is a solution to the problem and one that does not have to take a long time to do....check it out and sure you won't be disappointed!