That was certainly my case. When I bought my boat, the engine started overheating when going down the Nene, so I did have an external pipe fitted to the swim in Fox Marina. When the two holes for the pipes were drilled, my heart sunk. Still, it was a good decision as engine now happy and the capacity of cooling is 50% up. Also, I cannot see any problems with steering or reversing. The pipe might not be the most elegant solution, but it works and Foxes fit it to all their boats.