Chapter 4: Choosing the Right Thrust

Choosing the correct thrust is one of the most important decisions you'll make when selecting a trolling motor.

Thrust determines how effectively the motor can move, steer, and hold your boat in position. Too little thrust can leave the motor struggling in wind, current, or rough water. Too much thrust can increase cost, battery requirements, weight, and installation complexity without delivering a meaningful benefit.

The goal is not simply to buy the most powerful trolling motor available.

The goal is to choose enough thrust for your boat's fully loaded weight, hull design, fishing environment, and expected conditions—while maintaining a reasonable reserve for difficult days.

In this chapter, you'll learn how thrust is measured, how boat weight affects performance, why wind and current matter, how voltage relates to thrust, and how to avoid the most common sizing mistakes.

By the end, you'll be able to identify the appropriate thrust range for your boat with confidence.

What Is Trolling Motor Thrust?

Trolling motor power is commonly expressed in pounds of thrust.

Thrust measures the pushing force the motor can produce.

For example, a motor rated at 55 pounds of thrust can produce more pushing force than a motor rated at 30 pounds. A 112-pound or 115-pound motor can provide significantly more authority over a heavy boat than a smaller motor.

However, pounds of thrust should not be confused with:

• Horsepower
• Boat speed
• Battery capacity
• Runtime
• Motor efficiency

A higher-thrust motor does not necessarily make a boat dramatically faster.

Trolling motors are designed primarily for:

• Precise positioning
• Slow-speed movement
• Steering
• GPS anchoring
• Working shorelines
• Holding against wind and current

Their purpose is control, not high-speed propulsion.

Thrust Is About Control, Not Speed

Many buyers assume that doubling thrust will double boat speed.

That is not how trolling motors work.

Hull design, displacement, drag, propeller design, and water conditions all limit speed. Once a displacement hull reaches a certain point, adding more thrust may produce only a modest increase in speed.

The main benefits of additional thrust are:

• Better control of a heavier boat
• Faster steering response
• Improved performance in wind
• Better holding power in current
• More authority in rough water
• Reduced need to operate at maximum power
• Greater reserve capacity

The correct thrust level helps the motor control the boat more effectively under real fishing conditions.

Start With Fully Loaded Boat Weight

Boat weight is one of the most important factors in choosing thrust.

Do not size a trolling motor using only the manufacturer's published dry hull weight.

Dry weight may exclude:

• Outboard engine
• Fuel
• Batteries
• Passengers
• Livewell water
• Coolers
• Fishing tackle
• Anchors
• Electronics
• Safety equipment
• Trolling motor equipment
• Added decking or accessories

The number that matters is the boat's approximate fully loaded operating weight.

Example

Suppose a boat has a published dry weight of 1,500 pounds.

After adding:

• Outboard engine: 450 pounds
• Fuel: 250 pounds
• Batteries: 200 pounds
• Passengers: 400 pounds
• Gear and electronics: 250 pounds
• Livewell water and supplies: 200 pounds

The actual operating weight may be closer to 3,250 pounds.

That difference can significantly affect the correct trolling motor size.

A Common Starting Guideline

A frequently used starting guideline is approximately:

2 pounds of thrust for every 100 pounds of fully loaded boat weight.

Using that guideline:

Fully Loaded Boat Weight	Minimum Starting Thrust
1,000 lb	20 lb
1,500 lb	30 lb
2,000 lb	40 lb
2,500 lb	50 lb
3,000 lb	60 lb
3,500 lb	70 lb
4,000 lb	80 lb
5,000 lb	100 lb
6,000 lb	120 lb

This calculation provides only a minimum starting point.

It does not fully account for:

• Wind resistance
• Strong current
• High freeboard
• Offshore waves
• Hull design
• GPS anchoring
• Heavy vegetation
• Long runtime requirements

Most anglers should select some reserve capacity above the calculated minimum.

Minimum Thrust vs. Recommended Thrust

There is an important difference between the minimum amount of thrust required to move a boat and the amount recommended for dependable fishing performance.

A small motor may move a heavy boat in calm water.

That does not mean it can:

• Hold the boat in a strong wind
• Maintain GPS anchoring in current
• Steer effectively in waves
• Control the bow during sudden gusts
• Provide dependable performance all day

The minimum should be viewed as the lowest workable level under favorable conditions.

The recommended range should include enough reserve to handle the conditions you actually fish.

Why Reserve Thrust Matters

Reserve thrust gives the motor additional authority when conditions become more demanding.

It can help when:

• Wind increases during the afternoon
• Tidal current strengthens
• The boat carries additional passengers
• Livewells are full
• Waves lift the bow
• Vegetation collects around the propeller
• Batteries are partially discharged
• The motor must hold position for long periods

A motor that is barely adequate may spend most of the day operating near maximum power.

A properly sized motor can often perform the same work at a lower setting, providing smoother control and potentially better runtime.

How Much Reserve Should You Choose?

There is no single reserve percentage that works for every boat.

A modest reserve may be sufficient for:

• Small lakes
• Protected ponds
• Calm inland rivers
• Lightweight boats
• Occasional recreational use

A larger reserve is valuable for:

• Tournament fishing
• Tidal rivers
• Large reservoirs
• Heavy multi-species boats
• Bay boats
• Offshore center consoles
• Frequent GPS anchoring
• Strong wind and current

The more demanding the environment, the less you should rely on the absolute minimum.

Boat Length and Thrust

Boat length provides a useful starting point, but it should never be used by itself.

A lightweight 18-foot aluminum boat and an 18-foot fiberglass bass boat may require different thrust levels.

Likewise, a 22-foot bay boat can place much greater demand on a trolling motor than a low-profile 22-foot freshwater boat.

A general starting guide might look like this:

Boat Length	Common Thrust Range
Under 12 ft	30–45 lb
12–14 ft	40–55 lb
14–16 ft	45–70 lb
16–18 ft	55–80 lb
18–20 ft	70–100 lb
20–22 ft	80–115 lb
22–25 ft	100–120 lb
Over 25 ft	Highest available thrust, application dependent

These ranges are intentionally broad.

Always refine the decision using loaded weight, hull style, bow height, and operating conditions.

Boat Type Matters

Different boat designs create different thrust demands.

Kayaks

Fishing kayaks are light but can be affected strongly by wind.

Common needs include:

• Compact motor
• Low overall weight
• Efficient 12V operation
• Easy steering
• Moderate thrust

Too much motor can create handling, mounting, and battery-weight problems.

Jon Boats

Jon boats are usually light and move efficiently through calm water.

A small 12V motor may be sufficient for basic use.

Heavily modified jon boats with casting decks, multiple batteries, and several passengers may need considerably more thrust.

Aluminum Fishing Boats

Aluminum boats are relatively light but may have high sides that catch wind.

A 12V system may suit a small boat, while larger aluminum rigs often benefit from 24V.

Bass Boats

Bass boats require responsive bow control and strong steering performance.

Common choices include:

• 70–80 pounds of thrust on smaller boats
• 90–115 pounds on larger tournament boats

Deep-V and Multi-Species Boats

These boats are often heavier and have higher bows.

They may require:

• More thrust
• Longer shafts
• Greater battery capacity
• 24V or 36V systems

Flats Boats and Skiffs

These boats are usually light, but they operate in wind and tidal flow.

A quiet 24V saltwater system is common on larger models.

Bay Boats

Bay boats are heavier and often fish in strong wind and current.

Most benefit from high-thrust 36V saltwater motors.

Offshore Center Consoles

Large center consoles have high freeboard, substantial weight, and significant wind resistance.

They generally require:

• Maximum available thrust
• 36V power
• Long or extra-long shafts
• Large battery capacity

Hull Design Affects Thrust Requirements

Two boats with the same weight can respond differently to the same motor.

Flat-Bottom Hulls

Flat-bottom boats can move efficiently at low speed but may be pushed sideways by wind.

Mod-V and Semi-V Hulls

These offer a balance of stability and rough-water performance.

Their thrust needs depend heavily on weight and freeboard.

Deep-V Hulls

Deep-V boats usually create more resistance and often weigh more.

They may require additional thrust for precise control.

Fiberglass Hulls

Fiberglass boats are generally heavier than similarly sized aluminum boats.

They often benefit from higher thrust and voltage.

Pontoon Boats

Pontoons present a large surface area to the wind and can be difficult to control.

They may require more thrust than their weight alone suggests.

Catamarans and Twin-Hull Boats

These boats may have unusual mounting positions and water flow around the bow.

Motor sizing and installation should be evaluated carefully.

Wind Resistance Can Matter More Than Weight

A tall, lightweight boat can sometimes be harder to control than a low-profile boat that weighs more.

Wind pushes against:

• Consoles
• Windshields
• T-tops
• Enclosures
• High sides
• Raised bows
• Passengers
• Mounted equipment

This is known as windage.

Boats with high windage often need additional thrust to maintain heading and GPS position.

Examples include:

• Pontoon boats
• Deep-V boats
• Center consoles
• Boats with T-tops
• Boats with full windshield systems

Do not assume that low weight always means low thrust requirements.

Current Increases Power Demand

Current creates continuous pressure against the boat.

A motor that feels strong on a calm lake may work much harder in:

• Tidal inlets
• Rivers
• Spillways
• Bridges
• Narrow channels
• Coastal passes

GPS anchoring in current can require sustained thrust rather than short steering corrections.

Anglers who fish moving water should select more reserve thrust and battery capacity than those fishing protected lakes.

Waves and Rough Water

In rough water, the propeller may move closer to the surface as the bow rises.

The motor must also make frequent corrections to control position and heading.

Rough conditions increase demand through:

• Constant steering
• Repeated power changes
• Bow movement
• Propeller ventilation
• Greater water resistance

Thrust and shaft length work together in these conditions.

A powerful motor with a shaft that is too short may still perform poorly because the propeller cannot remain submerged.

Vegetation and Debris

Heavy vegetation increases load on the motor.

Grass, weeds, and fishing line can:

• Reduce propeller efficiency
• Increase current draw
• Slow the motor
• Create vibration
• Trigger protective shutdowns

Anglers who regularly fish thick vegetation may benefit from:

• Additional reserve thrust
• A weed-resistant propeller
• Brushless motor technology
• Higher battery capacity

However, no amount of thrust can fully compensate for a badly obstructed propeller.

Thrust and Voltage Are Closely Connected

Thrust availability generally increases with system voltage.

Common configurations include:

12V Motors

Typical thrust range:

• Approximately 30 to 55 pounds

Best suited for:

• Kayaks
• Small jon boats
• Small aluminum boats
• Light recreational use

24V Motors

Typical thrust range:

• Approximately 70 to 90 pounds

Best suited for:

• Medium-size fishing boats
• Bass boats
• Multi-species boats
• Larger aluminum boats
• Moderate wind and current

36V Motors

Typical thrust range:

• Approximately 100 to 120 pounds

Best suited for:

• Heavy bass boats
• Bay boats
• Offshore center consoles
• Large multi-species boats
• Demanding wind and current

Exact thrust ranges vary by manufacturer and product family.

Why Higher Voltage Helps

Higher-voltage systems can deliver greater power more efficiently.

For the same power level, increasing voltage can reduce the current flowing through the wiring.

This can support:

• Higher thrust
• Improved electrical efficiency
• Better sustained performance
• Reduced voltage drop
• More manageable cable requirements

However, higher voltage also requires:

• More batteries
• More storage space
• A compatible charger
• Additional wiring
• Greater system cost
• More installation planning

Voltage should be selected as part of the complete system, not as an isolated specification.

Does More Thrust Mean More Runtime?

Not automatically.

Runtime depends on:

• Battery capacity
• Motor efficiency
• Speed setting
• Boat weight
• Wind
• Current
• Propeller condition
• Battery chemistry
• System voltage

A larger motor may consume more power at full output.

However, if the larger motor can control the boat at a lower percentage of its capacity, it may operate more comfortably than an undersized motor running continuously at maximum speed.

Proper sizing usually provides better overall performance than choosing either an excessively small or unnecessarily large motor.

Brushed vs. Brushless Thrust

Two motors with similar thrust ratings may not feel identical on the water.

Brushless motors often provide:

• High efficiency
• Strong low-speed control
• Quieter operation
• Reduced maintenance
• Consistent torque

Traditional brushed motors remain effective and widely used.

The thrust rating still matters, but motor design, propeller efficiency, steering response, and software also influence real-world performance.

Do not compare motors using thrust alone.

GPS Anchoring and Thrust

GPS anchoring requires the motor to make repeated steering and power adjustments to hold the boat near a selected position.

Performance depends on:

• Available thrust
• Battery condition
• Shaft depth
• GPS accuracy
• Boat-response settings
• Wind
• Current
• Boat size
• Mounting location

An undersized motor may hold acceptably in calm water but lose position as conditions worsen.

Offshore and tidal-water anglers should size the motor for the strongest conditions they reasonably expect to encounter.

Bow Mount vs. Transom Mount Thrust

Thrust can feel different depending on where the motor is mounted.

Bow-Mounted Motor

A bow motor pulls the boat through the water.

This usually provides:

• Better directional control
• Improved steering
• More precise positioning
• Better GPS anchoring

Transom-Mounted Motor

A transom motor pushes the boat.

This works well for:

• Small boats
• Basic propulsion
• Portable setups
• Backup use

However, pushing from the stern may provide less precise bow control in wind.

For serious fishing applications, a bow-mounted motor often makes more effective use of available thrust.

Using Multiple Trolling Motors

Some boats use more than one trolling motor.

Examples include:

• Bow motor plus transom motor
• Dual transom motors
• Primary motor plus emergency backup
• Bow GPS motor plus kicker or auxiliary motor

Do not simply add the thrust ratings together and assume the boat will perform like a single motor with the combined rating.

Multiple motors can create:

• Different thrust directions
• Additional drag
• More battery demand
• Steering complications
• Mounting challenges

A multi-motor installation should be planned as a system.

Is It Possible to Have Too Much Thrust?

Yes, especially on smaller boats.

An oversized motor may create:

• Excessive weight
• Difficult handling
• More abrupt steering
• Unnecessary battery requirements
• Greater cost
• Mounting stress
• Reduced deck space

On a kayak or small jon boat, a large motor can affect balance and safety.

The goal is adequate power with reasonable reserve—not maximum power at any cost.

Thrust Recommendations by Boat Profile

The following examples provide general starting points.

Fishing Kayak

Typical setup:

• 30–55 pounds of thrust
• 12V
• Compact battery system

Important priorities:

• Weight
• Balance
• Mount strength
• Runtime

Small Jon Boat

Typical setup:

• 30–55 pounds
• 12V

Larger, heavily modified jon boats may need:

• 70–80 pounds
• 24V

16- to 18-Foot Aluminum Fishing Boat

Typical setup:

• 55–80 pounds
• 12V or 24V

Choose the higher range for:

• High sides
• Heavy loads
• Rivers
• Frequent wind

18- to 20-Foot Bass Boat

Typical setup:

• 70–100 pounds
• 24V or 36V

Tournament use often favors additional reserve.

20- to 22-Foot Bass Boat

Typical setup:

• 90–115 pounds
• 36V

Deep-V Multi-Species Boat

Typical setup:

• 80–115 pounds
• 24V or 36V

Higher bows and rough water often justify more thrust.

Flats Boat or Skiff

Typical setup:

• 55–80 pounds
• 12V or 24V

Larger models may require more power.

20- to 24-Foot Bay Boat

Typical setup:

• 100–120 pounds
• 36V

Offshore Center Console

Typical setup:

• Highest available thrust
• 36V
• Large-capacity battery bank

Some very large boats may need specialized installations or more than one positioning system.

Example 1: Small Aluminum Boat

Consider a 14-foot aluminum boat with:

• Dry hull weight: 300 pounds
• Outboard and fuel: 150 pounds
• Battery: 60 pounds
• Anglers and gear: 450 pounds

Estimated loaded weight:

960 pounds

Using the basic guideline:

960 ÷ 100 × 2 = approximately 19 pounds of minimum thrust.

However, a 20-pound motor would provide very little reserve.

A practical choice might be:

• 30–40 pounds for calm protected water
• 45–55 pounds for wind, current, or heavier loads

This example shows why the formula should be treated as a minimum rather than the final answer.

Example 2: 18-Foot Bass Boat

Consider an 18-foot fiberglass bass boat with:

• Hull: 1,500 pounds
• Outboard and fuel: 650 pounds
• Batteries: 200 pounds
• Passengers and gear: 500 pounds

Estimated loaded weight:

2,850 pounds

Basic minimum:

2,850 ÷ 100 × 2 = approximately 57 pounds of thrust.

A 55-pound motor might move the boat in calm conditions, but it would not be the ideal choice for serious fishing.

A more practical setup would usually be:

• 70–80 pounds of thrust
• 24V system

This provides better control and reserve capacity.

Example 3: 21-Foot Tournament Bass Boat

Consider a fully equipped tournament bass boat weighing approximately 4,000 pounds when loaded.

Basic minimum:

4,000 ÷ 100 × 2 = 80 pounds of thrust.

An 80-pound motor may be workable, but a competitive angler may prefer:

• 100–115 pounds of thrust
• 36V system

The larger system provides better control in wind, strong steering response, and more reserve for long tournament days.

Example 4: 23-Foot Bay Boat

Consider a loaded bay boat weighing approximately 5,000 pounds.

Basic minimum:

5,000 ÷ 100 × 2 = 100 pounds of thrust.

Because the boat will likely encounter:

• Tidal current
• Wind
• Chop
• High bow movement

A 36V motor in the 100- to 120-pound range would be more appropriate than selecting the minimum alone.

Example 5: Offshore Center Console

Consider a 28-foot center console with a fully loaded weight of 8,000 pounds.

Basic minimum:

8,000 ÷ 100 × 2 = 160 pounds of thrust.

That figure may exceed the rating of a single conventional trolling motor.

In this situation, the buyer must evaluate:

• The most powerful available motor
• Hull and mounting suitability
• Battery capacity
• Actual offshore conditions
• Manufacturer guidance
• Professional installation
• Whether a single bow motor is appropriate

The basic formula becomes less useful for very large boats because available motor configurations and real-world hull dynamics become the limiting factors.

Avoid Sizing Only for Calm Conditions

Many boats are tested or demonstrated on calm days.

Your motor should be selected for the more difficult conditions you realistically expect.

Think about:

• Afternoon wind
• Full passenger load
• Strong current
• Rough water
• Long fishing sessions
• Full livewells
• Heavy tournament gear

A system that works only under ideal conditions is not properly sized.

Avoid Buying Based Only on Boat Length

Retail charts often organize motors by boat length because length is easy to understand.

However, a better decision considers:

• Loaded weight
• Hull material
• Freeboard
• Windage
• Current
• Intended use

Boat length is useful, but it should not be the only input.

Avoid Buying Based Only on the Maximum Thrust Number

The highest thrust rating does not automatically make one trolling motor better than another.

Also compare:

• Shaft length
• Voltage
• Battery requirements
• Steering system
• Propeller design
• Motor efficiency
• GPS performance
• Mount construction
• Electronics compatibility
• Warranty and service

Thrust is one part of the complete system.

Account for Battery Performance Over Time

Batteries gradually lose capacity as they age.

Cold temperatures, incomplete charging, repeated deep discharge, and poor maintenance can also reduce performance.

A system with no reserve may feel adequate when the batteries are new but become disappointing later.

Selecting reasonable reserve thrust and battery capacity helps maintain performance over the life of the system.

Do Not Use Thrust to Compensate for the Wrong Shaft Length

A common mistake is assuming that a more powerful motor can overcome a short shaft.

It cannot.

If the propeller repeatedly breaks the surface:

• Thrust is lost.
• Noise increases.
• Steering becomes inconsistent.
• GPS anchoring suffers.

Correct thrust and correct shaft length must be selected together.

Do Not Ignore the Mounting Surface

Higher-thrust motors place more force on:

• Decks
• Mounting plates
• Brackets
• Fasteners
• Quick-release systems

Make sure the boat's bow is properly reinforced.

A motor that is correctly sized for thrust can still create problems if the mounting surface is weak.

Thrust Selection Checklist

Before choosing a motor, confirm:

✓ Your boat's approximate fully loaded weight

✓ Boat length and hull type

✓ Freshwater or saltwater use

✓ Typical passenger load

✓ Average wind conditions

✓ Current or tidal exposure

✓ Bow height and freeboard

✓ Use of GPS anchoring

✓ Required shaft length

✓ Available battery space

✓ Preferred system voltage

✓ Mounting strength

✓ Expected runtime

✓ Future equipment upgrades

Quick Thrust Decision Process

Use this step-by-step process:

Step 1: Estimate Loaded Weight

Add the hull, outboard, fuel, passengers, batteries, gear, livewell water, and accessories.

Step 2: Calculate the Minimum

Use approximately 2 pounds of thrust for every 100 pounds of loaded weight as a basic starting point.

Step 3: Evaluate Conditions

Increase reserve for:

• Wind
• Current
• Waves
• High freeboard
• Vegetation
• Heavy loads
• GPS anchoring

Step 4: Match Voltage

Determine whether the recommended thrust requires a 12V, 24V, or 36V system.

Step 5: Confirm Battery and Installation Requirements

Make sure the boat has room and carrying capacity for the complete system.

Step 6: Compare Appropriate Models

Compare motors within the correct thrust, voltage, shaft length, and environmental category.

Common Thrust-Sizing Mistakes

Avoid these errors:

• Using dry hull weight instead of loaded weight
• Buying only by boat length
• Choosing the absolute minimum
• Ignoring wind and current
• Assuming more thrust means much more speed
• Forgetting battery and charger requirements
• Installing an oversized motor on a small boat
• Choosing a powerful motor with the wrong shaft length
• Ignoring bow reinforcement
• Comparing thrust ratings without comparing the complete system

Frequently Asked Questions

How Much Thrust Do I Need for My Boat?

A common starting guideline is approximately 2 pounds of thrust for every 100 pounds of fully loaded boat weight.

Add reserve capacity for wind, current, waves, high freeboard, and GPS anchoring.

Is More Thrust Always Better?

No.

Additional thrust can improve control, but it also increases battery requirements, weight, cost, and installation complexity.

Choose enough thrust with reasonable reserve.

Will a Higher-Thrust Motor Make My Boat Much Faster?

Usually not.

Trolling motors are designed for low-speed control, and boat speed is limited by hull design and drag.

Is 55 Pounds of Thrust Enough?

A 55-pound motor is commonly suitable for kayaks, jon boats, small aluminum boats, and other lightweight boats.

It may be inadequate for a heavy bass boat, bay boat, or deep-V fishing boat.

Is 80 Pounds of Thrust Enough for a Bass Boat?

An 80-pound 24V motor is often a strong fit for many 17- to 19-foot bass boats.

Larger or heavily loaded tournament boats may benefit from a 36V motor with greater thrust.

How Much Thrust Does a Bay Boat Need?

Many 20- to 24-foot bay boats use 36V trolling motors producing approximately 100 to 120 pounds of thrust.

The correct choice depends on loaded weight, bow height, current, and shaft length.

Can a Trolling Motor Be Too Powerful for a Boat?

Yes.

An oversized motor can add unnecessary weight, cost, battery demand, and mounting stress—especially on kayaks and small boats.

Does GPS Anchoring Require More Thrust?

GPS anchoring does not create a separate thrust requirement, but it may require sustained power in wind and current.

Choose enough reserve to hold the boat in the conditions you expect.

Key Takeaways

Choosing the correct thrust begins with your boat's fully loaded operating weight—not its dry hull weight.

A useful minimum starting point is approximately 2 pounds of thrust for every 100 pounds of loaded boat weight. However, that figure must be adjusted for hull design, windage, current, waves, vegetation, passenger load, and GPS anchoring demands.

More thrust does not necessarily mean much more speed.

Its greatest benefits are stronger boat control, better holding ability, improved steering response, and additional reserve in difficult conditions.

Small boats may perform well with a 12V motor in the 30- to 55-pound range. Medium-size fishing boats often benefit from 24V systems in the 70- to 90-pound range. Heavy bass boats, bay boats, offshore center consoles, and other demanding applications commonly require 36V systems producing approximately 100 to 120 pounds of thrust.

The best choice is not the largest motor available.

It is the motor that provides enough power to control your fully loaded boat in the conditions you actually fish—without adding unnecessary weight, cost, or complexity.

Choose thrust as part of a complete system that includes the correct voltage, shaft length, batteries, charger, wiring, and mount.

When those components are properly matched, the trolling motor will perform more efficiently, provide better control, and give you greater confidence on the water.