Nigel,
Houdini sells these with polycarbonate as well, but they are junk. If all
you want to do is stay tied up, they are probably OK. I dropped 1500 pounds
Sterling on 2 companionway hatches a while back. These were sliders. No
matter how I installed them, they stuck and would never slide well. They
scratched and they leaked. I threw them away in the end and designed and
built my own out of stainless and armor glass.

Please do not confuse the different categories of glass. There are many and
they go by different names in different countries. Automotive glass in the
UK is called toughened glass. This glass is heat treated and cooled quickly.
This leaves the glass very hard and highly stressed. This is the wrong stuff
to use as hatches. It is also called plate glass. In the UK the glass you
need is armor glass. This glass is also heat treated but the process used
causes the glass to be stress relieved and it is delivered in an annealed
state. It is most commonly laminated with plastic in between panes of glass
for bullet proofing. It can be found up to 12mm thick. I use it 10mm thick
unlaminated. It is very scratch resistant. It doesn't fade and you can
literally beat on it with a hammer and bow it under severe load and it
doesn't break. It is the best, but it isn't cheap.

One responder mentioned Gebo Hatches. Even though they are made in France,
they are very good. I have 13 in use. They do not leak and parts are readily
available.
Steve


"Nigel" wrote in message
...
I need to buy a new deck hatch. The choice seems to be either a Lewmar 60
or a Houdini super 50 foredeck hatch. They are both the same size (they're
both the same size) The Lewmar has Perspex (12mm I think) and the Houdini
6mm toughen glass. Houdini are a lot cheaper and I quite like the idea of
toughened glass, but is toughened glass likely to shatter into little
squares if it's walloped by a clew or similar object