Helm

The helm is an object in The Sims 3: Island Paradise, which allows controlling houseboats if the Sim's household owns the houseboat lot.
The object is automatically placed on all houseboat lots. It can also be bought for any lot with Buydebug, but the helm won't be able to do much on lots that are not houseboats.
It has 3 available upgrades, all of which count uniquely towards the Tinkerer Handiness challenge: Foghorn, Engine Speed, and Autopilot.