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Boating Product Help Guides

Boat Propeller Help Guide

Boat Propeler Help Guide Image

▸ Knowing Which Prop Will Fit Your Engine

▾ Knowing Which Prop Will Fit Your Engine

The specifics of a propeller are all determined based on its RPM performance on your engine when running at wide open throttle (WOT). This appropriate range will be listed in your owner’s manual.

Every design feature of a propeller will affect its performance in a number of different ways. Because the variations are so complex, manufacturers have specified which engine models are designed to work with their particular propeller.

If you use the Prop Finder on our page, you will likely be given more than a few different propellers that will fit your particular engine. You will then be able to select different style variations based on your preferences.

▸ The Difference Between 3 Blades & 4 Blades

▾ The Difference Between 3 Blades & 4 Blades

3 blade boat propeller 4 blade boat propeller
3 Blades 4 Blades
Most popular Low fuel consumption
Lower cost Smooth cruising operations
Less drag gives higher top-end speeds High thrust for towing skiers & tubes

▸ Aluminum vs. Stainless Steel

▾ Aluminum vs. Stainless Steel

Aluminum boat propeller Stainless steel boat propeller
Aluminum Stainless Steel
Most popular Highest performance
Less expensive Power drives to tip of blades with no flex
Excellent choice for shallow water Excellent choice for deeper water
Easy to replace, but doesn’t last as long Tough, rustproof, easily repaired from dings
Flexible blades absorb shock and protect the lower unit in a collision Rigid blades don’t protect lower unit in a collision, but the prop itself lasts much longer

▸ Propeller Diameter & Pitch

▾ Propeller Diameter & Pitch

Selecting Pitch and Diameter

These factors can vary slightly with every motor, all depending on what you decide to use your boat for. You can go through our Prop Finder to find out which propellers will fit with your engine, and then choose one of the suggested pitches and diameters based on your preference.

Propeller diameter and pitch
Diameter

Larger diameter is generally better for pushing heavy loads and maneuvering at low speeds as well as getting excellent hole-shot because of the expanded grip on the water.

Smaller diameter propellers will spin faster making them a good choice for performance boats that need higher top end speeds.

A V6 outboard prop would range 13”-16” while a 10 horsepower propeller would be around 8”.

Propeller pitch

High Pitch

Low Pitch

Pitch is the distance a propeller travels in one revolution

Pitch

Definition: The distance (in inches) a propeller travels in one revolution if there is no slippage. Pitch affects the performance of a propeller more than any other aspect.

**Sustained operation with a pitch that is too low or too high will cause damage to the engine.**

High Pitch: (Lower RPM) Boats go faster at the top end speeds. A high pitch is typically used on larger boats.

  • If the pitch is too high for your engine, it will "lug" the engine, reducing both top speed and performance.

Low Pitch: (Higher RPM) Increases acceleration, fuel efficiency and pulling power. Low pitch is typically used on smaller boats.

  • If your pitch is too low, it will cause the engine to exceed its specified RPM at top end speeds.

▸ Pressed-In Hub vs. Interchangeable Hub

▾ Pressed-In Hub vs. Interchangeable Hub

The hub is the center of the boat propeller where the blades attach. The center of the hub will slide over the propeller shaft, and in many cases this is the point where exhaust exits the engine.

Propeller hub & splines

The splines of the hub must exactly match those of the shaft

Boat propeller with interchangeable hub Boat propeller with pressed-in hub
Interchangeable Hub Pressed-In Hub
Hub stays attached to the boat, while propeller easily slides on and off Hub is integrated to the propeller core
Easier and less expensive to frequently swap out Installed by being pressed in position by a high pressure press; usually done in a shop
Not every interchangeable hub propeller is sold as a set with the hub Most common choice for propeller hub design

▸ How to Test Your Propeller’s Performance

▾ How to Test Your Propeller’s Performance

When you have the right propeller and it is working properly, your boat’s engine will run within the manufacturer’s designated RPM when running at Wide Open Throttle (WOT). If it doesn’t, then you need a new propeller.

Step-By-Step:
  1. Make sure your gas tank is full but the overall load in your boat is light (do not go out with the maximum number of people on board).
  2. Run your boat for at least 5 minutes to ensure your engine is properly warmed up.
  3. Find a wide open piece of water with little or no other boat traffic.
  4. Give your engine full throttle and get it up to maximum speed.
  5. When at maximum speed, note and record your RPM.

If the RPM at full throttle and speed is outside (either below or above) of the manufacturer's recommendation, it is time to shop for a new propeller.

Test your propellers performance

▸ Boat Propeller Problems & Fixes

▾ Boat Propeller Problems & Fixes

Cavitation

Cavitation is any erosion, pock marks, or irregular edges on the surface of the propeller. This is mainly caused by the impact of air bubbles when a pocket of air forms on the backside of a propeller blade – usually when the propeller is turning too fast for its design.

How to Avoid The most important factor is to choose the correct propeller pitch for your engine.

You can also reduce the likeliness of prop cavitation by choosing stainless steel, or by adding a cupping design on the blades.

Boat propeller with cavitation damage
Impacts
Boat propeller with impact damage

Shallow Waters / Hard Obstacles Aluminum propellers are more susceptible to damage than stainless steel props, but are cheaper to replace. They will also absorb the shock of an impact better than stainless steel, which actually protects the lower unit from incurring extremely costly damage. This is the reason they are recommended for shallow water where rock collisions are more likely.

Silt and Sand The damage from soft material can lead to cavitation, reduced fuel economy, and reduced overall efficiency. A stainless steel prop will hold up to silt and sand exposure very well.

▸ Care and Maintenance

▾ Care and Maintenance

B. R. I. G.
Backup your boat propeller, just like you have a spare tire in your car. All-around performance propellers are typically a great option for backups. Replace old, worn-out propellers. Running on a bent, chipped, or pock-marked prop will lead to cavitation as well as expensive damage to the engine and stern drive. Inspect your propeller regularly for bent blades, nicks, and rolled tips, as well as any mud, aquatic plants, or animals. Grease the moving parts of the propeller with a marine-quality waterproof product. Use the grease before fitting the boat prop and as part of your routine maintenance procedure.

▸ Propeller Cup, Rotation, and Rake

▾ Propeller Cup, Rotation, and Rake

Cup

The propeller’s cup is the curved lip on the blade tip. Cupping a propeller will cause a decrease in RPMs, giving it high performance and minimizing cavitation under heavy loads.

Boat propeller cup and rake
Rotation

Propellers spin right (clockwise) or left (counterclockwise).

  • Dual propellers have two blades that spin in opposite directions.
  • Right-hand rotation is standard.
  • Left-hand rotation is mainly used for one engine in a dual motor application to balance performance across the two engines.
Rake

Rake is the angle of the tip of the blade’s tilt forward or backward in relation to the hub. The angle is measured on a line extending from the center of the hub through the center of one blade.

  • Aft (Negative) rake tilts away from the hub. This helps the bow of the boat get up and out of the water, which creates less drag and results in higher top end speeds.
  • Forward (Positive) rake allows for a larger propeller which will give quicker hole-shot for towing skiers.
Boat propeller rake angle

Bimini Top Help Guide

Boat Propeler Help Guide Image

▸ Choosing a Bimini Style

▾ Choosing a Bimini Style

Popular Bimini Top Types and Dimensions by Boat Style
Bass Boats
Bimini Top Type Length Height
3-Bow 6' 46"
Bay Style Fishing Boats
Bimini Top Type Length Height
3-Bow 6' 60"
Bimini Top Type Length Height
Universal Tower Top 5' 26"
Bimini Top Type Length Height
3-bow 4-bow 6' 8' 48" 54" 60"
Bimini Top Type Length Height
3-bow 4-bow 6' 8' 48" 54" 60"
Bimini Top Type Length Height
3-bow 4-bow 6' 8' 36" 46"
Bimini Top Type Length Height
3-bow 6' 46"
Bimini Top Type Length Height
4-bow 8' 48" 60"
Bimini Top Type Length Height
3-bow 6' 46"
Bimini Top Type Length Height
2-bow 5 ½ 42"
Bimini Top Type Length Height
2-bow 5 ½ 42"
Bimini Top Type Length Height
2-bow 5 ½ 42"
Bimini Top Type Length Height
4-bow 8' 36"
Bimini Top Type Length Height
Pontoon Boat Top Buggy Style Pontoon Top 8' 9' 10' 48" 54"
Bimini Top Type Length Height
Dual Pontoon Top 16' 48"
Bimini Top Type Length Height
Free Standing Pontoon Top 8' 48"
Bimini Top Type Length Height
Super Sport Top 3-bow 5' 6' 30" 35"
Bimini Top Type Length Height
Super Sport Top 3-bow 5' 6' 30" 35"
Bimini Top Type Length Height
3-bow 6' 36"
Bimini Top Type Length Height
2-bow 5 ½ 42"
Bimini Top Type Length Height
3-bow 6' 46"
Bimini Top Type Length Height
Super Sport Top 3-bow 4-bow 5' 6' 8' 30" 35" 36"
Bimini Top Type Length Height
3-bow 6' 36" 46"
Bimini Top Type Length Height
3-bow 6' 46" 54" 60"
Bimini Top Data
Standard Tower
2 bow 3 bow 4 bow
Width
  • Biminis flex to fit a range of about 6"
  • Buy the size that your boat's width falls in
47" - 84" 54" - 103" 61" - 103" 66" - 98"
Height
  • Choose based on desired vertical clearance
42" 30" 32" 35" 36" 46" 54" 36" 48" 54" 60" 26" Install higher or lower to reach desired height
Length
  • Bimini will extend half its length in front and half its length behind the mounting point
5 ½' 5' or 6' 8' 5'
Mount Top or side of gunwale Windshield (drilling required) Clamps on to boat tower (no drilling)
Storage
  • Mounting brackets allow bimini to lay flat when not in use
  • Braces or tracks available for maneuverable storage
Can be folded, or removed
Pontoon Bimini Top Data
Pontoon
Standard 4 bow Free Standing Dual Top Buggy Style
Width
  • Biminis flex to fit a range of about 6"
  • Buy the size that your pontoon's width falls in
96" - 102"
Height
  • Choose based on desired vertical clearance
48" 54" 48"
Length
  • Bimini will extend half its length in front and half its length behind the mounting point
8' 9' 10' 8' 8' when separated, 16' when zipped together 8'
Mount Side Rails (drilling required)
Storage
  • Mounting brackets allow bimini to lay flat when not in use
  • Braces or tracks available for maneuverable storage

▸ How to Measure for the Best Fit

▾ How to Measure for the Best Fit

Width

Choose where you want to mount your bimini, the most common mounting point is at the widest part of your boat. If this won’t work, then you can move the bimini mounting points up or back.

Once you decide on a good mounting point, measure a straight line between these points on either side of your boat.

  • Make sure not to measure up and over or around obstacles.
  • Biminis tops come in a range of widths. Choose the range in which your width measurement falls. The bimini will measure in the middle of the range, but can be flexed in or out.
Length

The mounting point is the center of the bimini, so the top will extend half its length in front and half its length behind the mounting point.

  • A 6' top will cover 3' forward, and 3' behind the mounting point
  • Check to see if your new bimini might conflict with existing antennas or ski pylons.
Height

Measure straight up from the mounting point. Keep in mind that the total standing height is the height of the bimini plus the height from the floor to the mounting point.

  • Consider how much clearance you want underneath the bimini to determine what height you should get.
  • With a 36" bimini, the support bows will cross the boat 36" above the mounting point.
  • A 36" bimini that is mounted 20" above the floor of the boat would have 56" of room underneath.

A tower bimini gets measured much in the same way as a standard bimini, but with a few key differences.

  • This bimini will only mount to the tower, which means no moving it forward or back in the boat.
  • Because of the no-drill installation it will be easily adjusted higher or lower on the tower for height preference.
  • All tower biminis are going to be the same height and length (26" H x 5' L)

▸ Fabric Comparison

▾ Fabric Comparison

Rated on scale of 1 (worst)- 5 (best)
Water Resistance UV Resistance Breathability Strength Colorfast Warranty
Sunbrella 4 5 5 4 5 Carver: 7 years Westland: 10 years
SunDura 5 5 3 4 5 7 years
Sharkskin Supreme 4 4 3 4 4 7 years
Vinyl 5 5 0 5 5 5 years
Poly-Guard 4 4 5 5 4 5 years
Sharkskin Plus 3 3 2 3 3 5 years
Double Duck 3 3 5 2 4 3 years
Sharkskin 2 2 1 2 2 3 years

▸ Slide Track and Brace Kit Options

▾ Slide Track and Brace Kit Options

Brace/ Rear Strut Kit (pic)

Braces hold your bimini in an upright position when open and stored. Also gives your bimini a more stable position when open.

  • Kits come with 2 braces and mounting hardware to fit seamlessly with your bimini.
Slide Tracks (pic)

Track mounts to gunwale of boat to allow bimini to slide into a more convenient lay- down storage position.

  • Kits come with 2 tracks and all matching mounting hardware.

▸ How to Clean Bimini Tops

▾ How to Clean Bimini Tops

For Mildew

1 cup Vinegar 1 cup Borax 2 cups warm water

Mix and apply to mildew spots, letting it sit for no more than 10 minutes. Scrub with a soft bristle brush and rinse well, allowing the fabric to dry completely.

For General Cleaning

¼ cup Dawn dish soap 1 gallon water

Fully wet the fabric and then scrub it down with a soft brush or cloth, give it a good rinse, and allow the fabric to fully dry.

Get tough spots clean with Fabric and Vinyl Cleaner

Apply Fabric Guard to the clean, dry surface to protect the fabric from the elements and extend their life.

NEVER

Put in washer and dryer Use powerful cleaners like bleach or detergent

Boat Ladder Help Guide

Boat Ladder Help Guide Image

▸ Coming Soon