Digger,
what sort of time are you looking at on the scrubber? And are you looking at DIY or purchasing one?
For purchasing one I'm looking at either a 3 hour scrubber from Tubby (
http://www.vk4tub.org/tubby/Abyss_Re...arts/index.htm), which works out at a tad over £300 after you've had to pay duty etc.
Or there is the posibility of a 6 hour scrubber from another source at approx. £400, (can't currently discuss it on the forum, I'll send you a PM).
Regards
Simon A
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and thinking about John's mate who can weld plastic, you could get the frenzy plastic welded off into 3 sections, inhale and exhale counterlungs and buoyancy bag (run like a BC)