It all depends
sa-...on where you want to go, how fast you want to go, how long you can put up with taking it longer than your neighbors, how much you like being out on the water, how much patience you have...We had a 1.2 HP one-speed Johnson on our WMP 8.4 dinghy for MANY years and loved it for even long trips, trips that were long enough to warrant bringing along a 1 gallon refill jug of gas (just to get to the fuel dock and get fuel and ice).Now we have a 9.9 hp on a 10.2 Zodiac. Love that too.Your boat, your choice.Good luck.Stu