At the Dive '97 show there were two new products that were creating something of a stir - one was the first production models of the Buddy Inspiration and the second was the PFP 90 lift bag from C-Kit Ltd. At LIDS 98 the PFP 90 was joined by a smaller brother, the PFP 50, and again the number of people that were seen walking around with the distinctive yellow and black bag certainly showed that the PFP 50 had created as much interest.

Over the past season I've used the PFP bags (mainly the PFP 90) to evaluate some of the claims made by the distributors of the bag - G & H Diving Services. The PFP 90 is designed for lifting loads of up to 90kg, the PFP 50 is (not surprisingly) intended for lifts up to 50kg.

The first thing you notice about the PFP bags is their unusual appearance. The 90 is a sort of elongated mushroom shape that tapers down to a long funnel or sock and the 50 looks very similar in shape to the balloons used by the likes of Richard Branson and Steve Fossett in their attempt to fly around the world. However this design isn't just so the bag will look different, it is based on the practical problems that lift bags face in general.

Open ended bags are at their best when they have a reasonably heavy payload slung beneath them. The problems begin when a fully inflated bag has a lighter object under it. Assuming that the bag has been carefully inflated using just enough air to start the lift, if this was done at a depth of greater than 10m, Boyle's law will dictate that the volume of air in the bag just prior to it hitting the surface will have doubled and as we increase the depth, this volume trebles, quadruples etc. This problem is compounded if the bag has been deliberately overfilled to drag the payload clear from silt or wreckage. The net result of this is that all too often the bag hits the surface, jumps clear, tips, spills air and follows its payload back down to the seabed.
The PFP bags have been designed with this flaw in mind. The elongated sock that hangs below the bag ensures that even if the main body of the bag jumps clear, there is still a good metre and a half below the surface trapping the air in.

When folded away into the bottom section of their socks the bags are certainly compact. The long slim PFP 90 sits easily to the side of a 12 litre bottle under a couple of bungie cords. With the D-rings facing the tank boot it can easily be reached and deployed single handedly. The smaller 50 can be stowed in a similar position but would be equally out of the way if attached to a harness D-ring and tucked under your arm.

Deploying the bags is very simple. Having arrived at the payload you can begin to rig the lift using either rope or the supplied attachment strops. Clipping the stainless steel snap hooks to the D-rings or tying the rope into the lifting strop with the bag still in its sock is a major convenience especially in low visibility where the last thing you want is the lift bag wafting all around you as the lift is prepared.

With everything secured, the bag is pulled from its sock and prepared for inflation. The strop is now pulled inside the sock and you can begin to inflate the bag, safe in the knowledge that the sock acts as a funnel for the air and stops the bag from potentially closing and 'snatching' closed either on your hand or inflator.

Once the bag has hit the surface another of the sock's design features comes into play. In a heavy sea the design is such that the sock will 'fold', trapping the air rather than spilling it and losing buoyancy.
Discussing the bag with other serious wreck divers, the major gripe was the price, as in an average season they expected to lose at least two to three bags. Identifying the main ways in which bags are lost, we came down to load strops snapping and bags tipping and spilling.

The issue of tipping and spilling has already been covered and as far as weakened load strops snapping and poor lifting of bags by boat handlers is concerned, this has been addressed by the design of the attachment webbing. By going right around the bag, the webbing distributes the load to a much wider surface and in addition provides an easy lifting point for the boat crew. When the webbing loop is pulled the load is held as sure as if it had been lifted directly from the seabed. The bag can collapse and sit out of the way as the webbing and payload are hauled in.

Perhaps as the PFP 50 & 90 begin to gain greater acceptance the statistic of losing two or three bags per year will become something unsatisfactory rather than routine.

One final use for the bags (mainly the PFP 50) that we are currently experimenting with is to use them as a team delayed decompression stage, but more about that at a later date.

	PFP 90	PFP 50
Lift capacity	90 kg	50kg
Balloon length	1000mm	820mm
Sock length	630mm	660mm
Folded length	350mm	220mm
Folded width	230mm	250mm
Retail Price	£136.00	£95.00

With a price tag of between £ 95.00 and £136.00 the PFP 50 & 90 may not be the cheapest lifting bag on the market and the bags probably aren't everyone's cup of tea. But then again not everyone is seriously into wreck diving and recovery.
PROs: Well designed and constructed. CONs: Price.