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I got round to trying the Sevy ‘packraft’, a cheapo PVC dinghy with the outer hull cut off to make it less wide and hopefully more functional.
Compared to the single-chambered Alpacka, blowing it up takes a while. The floor is made of two interlinked ribbed chambers which require a ‘spike’ beach ball inflation adapter that fits on the end of the K-Pump (right). The main chamber fills quickly enough with the K-Pump – a one-way Boston valve ensures you get a good fill of the elastic material and it’s always a surprise to see it stay that way according to the SevyGauge™.
Even then, on the riverbank alongside the Yak it did look very small and rather low in draught so that even with a dry suit, I wasn’t convinced I wanted to get in off a steep, muddy bank. So I set off upriver to Sluice Weir in the Yak, towing the Sevy and intending to shoot the chute for a bit of fun. On the way I spotted a striking blue bird – never seen one of those before. Do you get bluebirds in Kent in mid-winter?
I got in the boat as gently as I could but it didn’t take long to have an inverted Archimedean revelation: the mass of the paddler was nearly equal to the peak buoyancy at the rear of the craft. That’s partly why Alpacka came up with the fastback tail in 2011. Unlike Archimedes, I didn’t jump out yelling ‘Eureka’. I just sat still thinking ‘is it spilling over behind me and if not, why does my back feel cold?’ I took a couple of pics behind my back (below) to establish plimsoll levels, then set off slowly across the pool, with the trusty Alpacka tender bobbing along behind in case the Sevy sank.

This was not relaxed or efficient paddling like in the Yak. I arched forward trying to offload the stern while pulling gingerly through the water for fear of initiating a possibly catastrophic water-bounce that would fill the boat. The Sevy sagged feebly under the weight of my butt and feet, just as I’d seen Jeff’s do on the Fitzroy. However Alpacka do it, it’s the rigidity in their hulls that makes them as good an airboat can be. The multiple coatings on the non-stretch fabric must have a lot to do with that. As expected the short, round Sevyslackraft yawed quite badly, even with the Alpacka in tow to act as a rudder. But that always happens first time out in one of these boats until you adopt a smoother technique. Either way, I was relieved to be wearing a drysuit.
As I bimbled around trying not to sink, the nearby weir boom opened up without warning and suddenly the Medway was kicking out a current such as it had not seen since the end of the last Ice Age. I could barely make headway in the Sev so allowed myself to be swept back to the canoe portage pier where I hopped back into the Yak. Within just a few minutes the river had risen 6 inches or more. I thought it had appeared rather over-full upstream in Tonbridge where I had driven through earlier.
Anyway, the 5-minute Sevy Slackraft trial were complete. To paraphrase Right Said Fred, I’m… Too Hefty for My Boat, although it will make a nice packraft for the Mrs who’s a little over half my weight of 95kg + winter ballast.
So, packboating newsflash: the Sevy blow-up boat is not for bloaters like me. But as it’s so light I could still see a use for it as a tow barge for a bike or an extra huge payload (not that you could realistically walk with such a load). Maybe a really long river stage, or one where you want to be well equipped on arrival with a huge tent or something.