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FORUM CHAT Spin doctor?

kieronriley says I have an 18ft Shetland, and it has a Johnson 3-cylinder 70hp VRO engine with a 13 3/4 x 15 propeller. If I’m on my own it will get on the plane, but two up or more and it won’t get up, however hard I try. The propeller is very, very close to the cavitation plate. Does anyone have a similar boat who can give me some advice? I’m thinking maybe I should go for a smaller diameter prop?

Bouba says On a small planing boat, it’s essential to get the weight up front, but Shetland boats don’t allow anyone to sit on the bow so you’ll need to weigh it down with something else . You can do this by ballasting the bow with bags of sand or bottles of water and by putting a Doel-fin foil on the outboard.

Brucek says Trim tabs work a treat for getting out of the hole quickly and being able to plane at lower speeds. Try these basic Smart Tabs from www.nauticusinc. com. However, the first thing I’d do is take your boat and trailer to a weigh bridge and make sure it’s the correct weight. If it’s not, check any foam-filled chambers for water retention. Qbhoy says Check it’s not saturated with water. Also check the engine compression. Something is definitely not right. That boat/engine/prop combo should have no bother planing and achieving close to 30mph. A friend had a Shetland Family 4 with a Mercury 60hp and 15in prop. It would plane no bother with three adults without any additional weight forward. Although I should add, that perhaps 13in diameter is a bit much. I’m pretty sure the above mentioned had an 11 x 15in or thereabouts.