3.5 tonne boat should be in a pen at FSC not behind a car.

I'd tow it with a 100 or 200 series TD or an F250. Not a Landrover Discovery (which is rated to tow higher than both of those other more capable vehicles)

I once saw a Bertram 25 overpower the rusty post on the front of the trailer and cut a nice big Vee through the roof of a 60 series 'Cruiser when he did an emergency stop.