I agree with the reverse in, stern line, forward gear approach. But if you are permanently, or at least annually, at the marina, why not get them to fit a cleat halfway along the catway/short pontoon? That way, a line from bow cleat to forward cleat on pontoon, then up to deck centre cleat, back to pontoon centre cleat and then to stern cleat, should keep things tight. I'm in Canet, prone to the Tramontane and its kept my boat safe for a couple of years. I should add that I also use double stern lines and double the lines too from end of pontoon to the bow - because I need to really.