59° North Sailingvideo
Props // Rerun
September 29, 2026 · 47 min · 181 views · Gosport
What this video covers
Selecting a sailboat propeller requires balancing engine load, shaft RPM, and vessel speed to maximize efficiency and prevent engine damage. A propeller’s performance depends on its diameter and pitch, which must be sized to match the engine’s reduction gear ratio.10:02 Fixed-blade propellers offer simplicity and lower cost but lack the efficiency of feathering or self-adjusting models.14:29 Feathering propellers, such as the Maxprop, reduce drag while sailing, while self-pitching designs like the Autoprop function similarly to constant-speed aircraft propellers, automatically adjusting pitch to optimize torque and engine load across varying speeds.14:27
Engine loading is critical; under-loading a diesel engine can lead to cylinder glazing and carbon buildup, while over-pitching a propeller can bog down the engine and void warranties.31:47 Hydro-generators like the Watt & Sea also require specific propeller sizing based on boat speed, as faster vessels require smaller blades to maintain optimal turbine revolutions.24:40 Choosing between these systems involves weighing the high initial cost of advanced propellers against the mechanical benefits of proper engine loading and improved propulsion efficiency.45:08
Boats in this video
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