Abstract: A float-type flowmeter has a flow detecting surface, such as a fin, for pointing its inlet opening, which receives a portion of the flow to be measured, into the flow. Preferably the flowmeter, its inlet opening, and its fin, are all mounted to rotate as a unit, and the flowmeter is designed for measuring wind velocity on sailboats. This flowmeter is designed to be mounted on, and rotated around, a mast supporting wire, such as a shroud. The flowmeter should have counterweight so that gravity will not tend to prevent it from rotating around its wire when that wire is tilted. Similarly the inlet opening should be relatively small compared to the cross section of the float chamber, so that as the flowmeter tilts, the area of the inlet opening projected into a horizontal wind flow will decrease wind flow into the flowmeter, so as to compensate for the tilt. Preferably the flowmeter is designed so its float will not be visually obscured from upwind by the elongated structure around which it rotates.