Interesting website. I recieved one of these kits from my local police today and I will be marking our valuable stuff with it over the weekend. When I say our I mean my sib, outboard, pump.et al.
If you scroll to (DNA ASSET MARKING) on this site you will find a marine version for only 32 and one for 42 quid! It might just deter some thieves and could help to recover stolen equipment too.