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Thanks for your comment on my user page. I took a look at your map at the link you left, and it is not bad at all. Why dont you write up a site article and use it on Wikitravel? As far as I know Wikitravel has nothing yet on diving in the UK. Since there are a lot of divers there, and quite an active bunch, it would be great to have something for them.
The style of the map only becomes seriously important when you are pushing an article for star status. Up to there, anything is better than nothing, as long as it is not a copyright violation, and your map is already compatible, even if someone else uploaded it.