So the solution was to tow him. I was quite happy to do this as it gave me the chance to try out a tow rope I had on board the kayak all set up for just this kind of occasion. Here the yellow tow rope with its little float is clipped onto the inflatables bow loop.
I think this experience shows up the limitations of inflatable boats compared with displacement type hulls made of various materials. I have a small inflatable dinghy which works well with a small outboard motor but which is pretty much impossible to row into the wind when it is very choppy and windy making it dangerous in anything other than very moderate conditions.
Made of polyethylene I have found the hull pretty flexible and forgiving, especially when I have found myself dumped on the top of rocks by a receding swell whilst engaging in what us kayakers call, "Doing a bit of rock gardening".
Perhaps the biggest lesson of this little trip (or reminder really) was the value of Whanau (family). I love doing stuff with the Bros!