--- > Quick answer: Pontoons need torque and hole shot, not just top speed, and length alone does not pick the motor. A 60 CT is a lighter 18 - 20 ft two-log cruise/fish comparison; 90 - 115 CT is a heavier 18 - 22 ft family comparison. Whether Command Thrust is offered in a...
Quick answer: Pontoons need torque and hole shot, not just top speed, and length alone does not pick the motor. A 60 CT is a lighter 18–20 ft two-log cruise/fish comparison; 90–115 CT is a heavier 18–22 ft family comparison. Whether Command Thrust is offered in a given horsepower depends on the exact model; check Mercury's current model specifications. A 150 is a different model where the hull is rated for it. Compare only where this pontoon's documented power and weight limits, steering, and planned loads support it. Quote at mercuryrepower.ca.
Pontoon HP decision
How big is your pontoon and how do you load it?
Tube count and use case matter more than the HP number alone.
16 to 18 ft two-tube, cruising and light fishing
- ✓6 people maximum, no active water sports
- ✓Sheltered Kawartha bays, short runs
- ✓Fuel economy and quiet matter
- ✓You want the more affordable setup
Example: 90 HP CT where the hull's limits and a light cruise load support it
20 to 22+ ft tritoon, full crew with water sports
- ✓8 to 10 passengers, tubing or skiing weekly
- ✓Open water on Rice Lake or larger Kawartha lakes
- ✓Fast hole shot with the boat loaded matters
- ✓Long-term hold, you want the right motor once
Example: 150 FourStroke. 200 HP is a larger-tritoon comparison.
When in doubt:CT only where Mercury offers that exact model and the pontoon's documented power, weight, steering, and load limits accept it. Horsepower is the other half of the same check.
The gearcase is the part most people overlook
Customers shopping for a pontoon motor focus on the HP number. The gearcase is an afterthought, and that's the wrong order of priorities.
A 90 HP Command Thrust and a standard 90 HP look almost identical on a spec sheet. Same horsepower. Same motor family. But Command Thrust uses a larger gearcase, a larger prop, and a torque-tuned gear ratio that's built for heavy boats. On a pontoon, that means faster lift to cruise when you have six people aboard, better load-carrying, and a boat that feels like it has more motor than the number would suggest.
We default to Command Thrust on most pontoon repowers at HBW. Customers who push back on the small price difference, and then see the boat run with the right gearcase, get it immediately. For installed cost ranges on pontoon repowers in this HP band, see the boat repower guide.
What changes the right Mercury for your pontoon
Pontoon length and tube configuration. Two-tube pontoons under 20 ft have different needs than 22 ft tritoons. The hull matters.
Use case. Cruising and fishing without water sports is a very different ask than active tubing, skiing, or wakeboarding. Same boat, different right answer.
Passenger and gear loading. A 22-foot pontoon with eight people and a full cooler needs more motor than the same pontoon with two adults and a fishing rod.
Where you boat. Sheltered Kawartha bays vs. open water on a big lake vs. running the Trent-Severn system all change the practical HP minimum.
Compliance notice. Use the manufacturer's maximum recommended safe power for the exact pontoon model, then check tube configuration, transom, steering, motor weight, and load. Similar-looking pontoons can carry different ratings.
Best Mercury for pontoons by use case
| Pontoon use case |
Practical Mercury range |
HBW note |
| 18–20 ft two-log, cruise/fish |
60 CT or 90 CT examples |
Lighter vs heavier two-log cruising |
| 20–22 ft, family cottage |
90–115 CT examples |
Family load on Rice Lake, where the plate allows |
| 22–24 ft, active water sports |
115 CT or 150 FourStroke examples |
Check the exact model's gearcase specifications |
| Large tritoon or performance |
150+ examples |
Confirm rating, steering, transom, and motor weight |
18–20 ft two-log pontoon, cruising and fishing only
Example to compare: 60 HP Command Thrust FourStroke on a lighter 18–20 ft two-log used for cruising and fishing, where Mercury offers that CT model and the boat's limits support it. See the 115 vs 150 dealer guide for the same comparison. A 90 CT suits heavier loads or longer runs on some hulls.
18–20 ft pontoon, family use with occasional water sports
Example to compare: 115 HP Command Thrust FourStroke where occasional family water sports, this pontoon's limits, and an available CT model line up. Hole shot still depends on hull, prop, and the day's load. 90 CT remains the heavier cruise example; 60 CT the lighter two-log cruise example.
20–22 ft pontoon, active water sports
Example to compare: 150 HP FourStroke (standard gearcase), where the documented hull limits and loaded use support it. Compare the exact 150 HP model and its standard gearcase with an available 115 CT configuration; a family name alone does not establish gearcase fitment. Towing performance depends on the exact hull, propeller, load and conditions. Above 150 HP on a traditional two-tube pontoon starts to return diminishing gains because the hull design itself limits top speed.
Tritoons (three-tube), 22–24 ft
Best fit: 150 HP and up (standard gearcase). The third tube changes the hydrodynamics and lets the boat reach higher speeds with adequate HP. For 22–24 ft tritoons with active water sports, 200 HP FourStroke (standard gearcase) is typical.
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Why Command Thrust makes the difference on pontoons
Pontoons are unique among recreational hulls:
- Blunt-fronted, the noses push water rather than slice it
- Heavy, aluminum tubes, fibreglass furniture, full hardware add up fast
- Wide, more drag than a similar-length runabout
- Slow to come up on cruise, the hull design fights the transition from displacement to cruise
Standard gearcases are built around runabout hydrodynamics. Command Thrust matches pontoon physics:
- The bigger gearcase nose handles heavier load without cavitation
- The larger prop pushes more water per revolution for better hole shot
- The torque-tuned ratio gets the boat up on cruise sooner at lower speeds
- The lower cruise speed lets pontoons run efficiently
The result: noticeably stronger hole shot when loaded, faster time to cruise, better load-handling for water sports. None of these come from extra HP, they come from the gearcase.
Common pontoon motor mistakes
1. Skipping Command Thrust to save money. The single most common pontoon repower mistake. Customer picks the standard 90 HP, and trades up to Command Thrust within two or three seasons. Pay once.
2. Choosing power without the loaded use case. For water sports, compare an available 115 CT or 150 FourStroke configuration only where the hull permits it. These are examples, not a universal minimum or a towing-performance guarantee.
3. Buying too much for cruising only. A 200 HP on an 18-foot pontoon used for sunset cruises is overkill and extra fuel burn. The 90–115 CT range handles cruising elegantly.
4. Wrong prop on a Command Thrust gearcase. Command Thrust gearcases need Command Thrust props, the larger diameter and different geometry aren't compatible with standard props.
5. Forgetting about the trailer. Pontoon trailers on older setups are often the limiting asset. Check trailer condition before committing the repower budget.
Tritoon vs two-tube: when to step up
Customers sometimes ask whether to upgrade their two-tube pontoon to a tritoon during a repower. The honest answer: switching from two-tube to tritoon is a new pontoon purchase, not a repower project. The hull is the asset, you can't cost-effectively retrofit a third tube to most existing two-tube pontoons.
If your needs have shifted toward active water sports and your two-tube isn't keeping up, the conversation is really about whether to sell and buy a tritoon. We sell new Legend Boats and are happy to work through that decision with you.
Mercury Boost on a pontoon: when it actually helps
Mercury Boost is a software calibration. Mercury reports 5% to 21% quicker acceleration from zero to top speed in its tested boat-and-engine applications. That is an acceleration comparison, not a 5% to 21% increase in top speed, and it is not a guaranteed result for a given pontoon. Mercury says Boost does not change top speed or time to plane; boat configuration and operating conditions affect the result. It does not add peak horsepower at wide-open throttle. On a pontoon, that distinction matters more than on most other hull types.
When Boost helps on a pontoon:
- You run a tritoon with a 200-300 HP V8 Pro XS and tow tubes or skiers regularly. Faster mid-range punch out of the hole can be noticeable on an eligible, correctly powered setup.
- A Mercury dealer has confirmed the exact serial number, control system and installed calibration against the dated Canadian lists, rather than treating a serial cutoff alone as automatic eligibility.
- You already have enough peak HP for the boat loaded. Boost sharpens acceleration, not top speed.
When Boost does NOT help on a pontoon:
- You run a standard two-tube pontoon with a 90 or 115 Command Thrust. CT is the right answer here. The 115 CT is not on the Boost eligibility list, and the gearcase plus prop pairing is already optimized for hole-shot on a standard pontoon.
- You spend 80 percent of your time at steady cruise. Boost is invisible at constant throttle.
- The underlying motor is undersized for the hull. Boost will not fix that. You need a bigger motor, not a calibration upgrade.
The honest pontoon-specific framing: For a typical two-tube pontoon in the Kawarthas, the right answer is a 90 or 115 Command Thrust FourStroke. For a tritoon or a pontoon used for serious watersports, a 200-300 HP V8 Pro XS with factory Boost (or the dealer-installed Boost calibration on an eligible serial) is the upgrade path. Boost is not a substitute for the right base motor.
For full Boost eligibility detail by motor family and serial range, see our Mercury Boost software upgrade eligibility guide.
Ready to repower your pontoon?
Build a quote at mercuryrepower.ca. The system asks for your hull info and use case and recommends the right HP class and gearcase.
About the author
Jay Harris helps run Harris Boat Works, a third-generation family marina in Gores Landing on Rice Lake, established in 1947. HBW is a Mercury Marine Premier Dealer and Legend Boats dealer serving Rice Lake, the Kawarthas, and Ontario boaters who want straight answers before spending real money. Read Jay's full bio.
