Petermcc, that sounds reasonable but it has been contradicted here by other ppruners who stated it was redesigned specifically to make it less likely to be able to puncture a dinghy.
Stichbitch, I appreciate that and am pleased to hear there is now a decent knife...my (fallible) memories from the 80s are of something pretty useless in the PSP. As an aside, does it now contain a warm hat?