Wire it right, prop it right and tow it home
Size the wire for any circuit, pick the right prop, and keep the outboard and trailer ready for the water.
What do you need?
Check a prop, wire a circuit, or get the motor ready for winter.
Check your prop
Pitch, diameter and blade count, starting from your engine's rated full-throttle RPM.
Open the prop guide →Wire a circuit
Wire size by amps and length, and diagrams for bilge pumps, battery switches and trolling motors.
Open the wire gauge chart →Winterize the outboard
Fuel, flushing, fogging and gear oil, in the order to do them.
Open the winterizing guide →What the site covers
The wiring, the props and the upkeep behind an outboard boat.
Props and performance
Choosing a prop, three blades or four, cupping, shaft length and a faster hole shot.
12-volt wiring
Wire gauge, bilge pumps, battery switches and trolling motors, drawn as diagrams.
Trailers and upkeep
Trailer lights and bearings, backing down the ramp, lower unit oil, winterizing and serial numbers.
Practice on dry land
Short games built around real boating skills. Free, no signup.
Trailer Backer
Back the boat down the ramp, where the trailer goes the opposite way from the wheel.
Play →Dock It
Stop alongside in calm water, then with the wind pushing you onto the dock and off it.
Play →Hole Shot
Prop and trim, then throttle.
Play →Every guide on the site
Calculators, wiring, props, boat handling, trailering and upkeep.
Prop slip calculator
Enter RPM, gear ratio, pitch and GPS speed to see how much of your prop's pitch the boat actually travels.
Prop pitch calculator
Up, down or keep it?
Boat speed calculator
What a bigger motor or a lighter load would do to your top speed, worked out from the speed you run today.
Two-stroke oil mix
Ounces of oil for any tank and ratio.
Boat name generator
Fishing puns, classic names and pontoon jokes, a fresh batch of eight with every press, each with its length for the lettering.
Marine wire gauge chart
Find the wire size for any 12-volt circuit from its amps, the length of the run and the voltage drop you can accept.
Bilge pump wiring
Float switch and panel switch, drawn.
Battery switch wiring
The 1-2-Both-Off selector.
Trolling motor wiring
How to join batteries in series for a 24 or 36-volt motor, where the breaker goes, and the wire size each maker lists by length.
What size trolling motor
Thrust by weight.
Trolling motor shaft length
How to measure, with each maker's chart.
How to choose a boat propeller
Start from your engine's rated full-throttle RPM, then work out pitch, diameter, blade count and material.
3 blade vs 4 blade prop
Plus aluminum vs stainless, and the pitch drop.
Propeller cupping
What cup does.
Hole shot and trim
Trim, weight, prop, trim tabs and hydrofoils, in the order to try them when the bow hangs high and the boat struggles to get up.
Outboard shaft length
Transom and motor, measured.
How to drive a pontoon boat
First time at the helm?
How to dock a boat
Wind on the bow, onto the dock or off it, plus spring lines for tight spaces and tips for pontoons.
How to back up a boat trailer
Hand low on the wheel.
Boat trailer wiring diagram
Wire colors for the 4-pin flat plug, how to test each circuit with a multimeter, and the usual fixes when trailer lights won't work.
How to repack trailer bearings
Step by step, with each maker's spindle nut steps.
Lower unit oil change
Drain first, fill from the bottom up, and use the gear oil your outboard's maker lists.
How to winterize an outboard
Fuel, flushing and fogging.
Outboard serial number location
Find the tag.