I chose the Osprey Marine Secure Hatch lock Osprey Marine and I have to say it is top notch. It is priced at £125 and you’ll need a good quality marine padlock to go with it.
You need to take care positioning and drilling the holes and the supplied template is a big help. Although I did have a few issues mainly through not trusting the template as I should have done.
Once fitted it is not only a solid physical deterrent, visually it looks the part also.
A Dragon's Tale 