Pro-Line 18 Flats 2011 vs Pro-Line 21 Sport 2005 - Boat Spec Comparison

Q: Which is easier to trailer — the Pro-Line 18 Flats 2011 or the Pro-Line 21 Sport 2005?

For trailering, the Pro-Line 21 Sport 2005 has the edge at 26 lbs dry weight versus 1 548 lbs for the Pro-Line 18 Flats 2011. Add a motor (typically 300–500 lbs for an outboard in this class), gear, and a partial fuel load and the difference grows. Lighter is friendlier on smaller tow vehicles and on fuel economy while hauling.

Q: Which boat can handle a bigger outboard?

The Pro-Line 21 Sport 2005 is rated to a maximum of 200 hp, giving it the larger power ceiling. The Pro-Line 18 Flats 2011 tops out at 115 hp. Keep in mind that maximum ratings are just that — matching the motor to the actual load and usage pattern usually matters more than chasing the ceiling.

Q: How many people can each boat hold?

The Pro-Line 18 Flats 2011 is Coast Guard rated for 5 passengers, while the Pro-Line 21 Sport 2005 is certified for 6. Note that legal capacity and comfortable capacity aren't always the same thing — on a full day out, most experienced boaters aim for about 80% of the rated number to keep things comfortable.

Q: Which boat is wider, and does it affect trailering?

The Pro-Line 21 Sport 2005 measures 101" wide, compared to 96" for the Pro-Line 18 Flats 2011. The US standard-width towing limit is 8’6" (102") in most states — anything over that may need a wide-load permit. Confirm your specific route requirements with each state's DOT.

Q: Which boat has the larger fuel tank — the Pro-Line 18 Flats 2011 or the Pro-Line 21 Sport 2005?

The Pro-Line 18 Flats 2011 has the bigger tank at 27 gallons, versus 7 gallons on the Pro-Line 21 Sport 2005. That 20-gallon difference translates to roughly 60–100 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.

Q: Are the Pro-Line 18 Flats 2011 and Pro-Line 21 Sport 2005 from the same manufacturer?

Yes — both the Pro-Line 18 Flats 2011 and the Pro-Line 21 Sport 2005 are built by Pro-Line. That means shared dealer networks, common parts availability, and consistent build quality across the line. The choice between them is essentially a question of how much boat you need, not which brand you trust.

Boat Comparison

Pro-Line 18 Flats 2011 vs Pro-Line 21 Sport 2005

Pro-Line

Pro-Line 18 Flats 2011

2011

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Pro-Line

Pro-Line 21 Sport 2005

2005

View full specs →

Detailed Evaluation & Buyer Recommendation

Pro-Line 18 Flats 2011 vs Pro-Line 21 Sport 2005 — Same Brand, Different Boat

The Pro-Line 18 Flats 2011 vs Pro-Line 21 Sport 2005 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.

The power gap is worth calling out. Rated to 200 hp, the Pro-Line 21 Sport 2005 has a 85-hp advantage over the Pro-Line 18 Flats 2011's 115-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Pro-Line 18 Flats 2011 carries 27 gallons versus 7 gallons in the Pro-Line 21 Sport 2005. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

For family outings this is probably the sharpest distinction between the two. The Pro-Line 21 Sport 2005 is rated for 6 passengers, while the Pro-Line 18 Flats 2011 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Pro-Line 21 Sport 2005 could be the deciding factor.

Bottom line: Choose the Pro-Line 21 Sport 2005 if your priority is putting more people on the water — it handles 6 passengers and at 0,0 ft it has the deck room to back that rating up comfortably. The Pro-Line 18 Flats 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.

General Boat Info

MakePro-Line

Model18 Flats

Model21 Sport

Model Year2011

Model Year2005

Measurements / Dimensions

Beam8 ft. 0 in

Beam8 ft. 5 in

Beam - Meters2.44

Beam - Meters2.57

Beam - Inches96

Beam - Inches101

Deadrise13°

Deadrise19℃

Depth - DetailCockpit: 11 in

Depth - Detailnot available

Depth - Centimeters27.94

Depth - Centimetersnot available

Depth - Inches11

Depth - Inchesnot available

Draft [max] - Detail9 in

Draft [max] - Detail15 in

Draft [max] - Meters0.23

Draft [max] - Meters0.38

Draft [max] - Inches9

Draft [max] - Inches15

Weight - DetailHull: 1,548 lbs

Weight - Detail2,600 lbs

Weight - kg702.16

Weight - kg1179.34

Weight - lbs.1548

Weight - lbs.26

Length - Feet18.33

Length - Feetnot available

Length overall - Detail18 ft. 4 in

Length overall - Detail21 ft. 8 in

Length overall - Meters5.59

Length overall - Meters6.6

Length overall - Inches22

Length overall - Inches26

Body / Hull

Hull materialFiberglass

Hull materialnot available

Hull typeModified Vee

Hull typenot available

Engine and Drivetrain

Engine makeSuzuki or Evinrude or Mercury

Engine makenot available

Engine model4-stroke (Suzuki or Mercury engine) E-Tech (Evinrude engine)

Engine modelnot available

Fuel tank capacity - Detail27 gal

Fuel tank capacity - Detail70 gal

Fuel tank capacity - Liters102.21

Fuel tank capacity - Liters264.98

Fuel tank capacity - Gal27

Fuel tank capacity - Gal7

Fuel typeGas

Fuel typenot available

Drive typeOutboard

Drive typenot available

Horsepower90 hp

Horsepowernot available

Engine max115 hp

Engine max200 hp

Trailer Info

Trailer - Weight2,328 lbs

Trailer - Weight3,700 lbs

Pro-Line 18 Flats 2011 vs Pro-Line 21 Sport 2005 — Common Questions

Which is easier to trailer — the Pro-Line 18 Flats 2011 or the Pro-Line 21 Sport 2005?

For trailering, the Pro-Line 21 Sport 2005 has the edge at 26 lbs dry weight versus 1 548 lbs for the Pro-Line 18 Flats 2011. Add a motor (typically 300–500 lbs for an outboard in this class), gear, and a partial fuel load and the difference grows. Lighter is friendlier on smaller tow vehicles and on fuel economy while hauling.

Which boat can handle a bigger outboard?

The Pro-Line 21 Sport 2005 is rated to a maximum of 200 hp, giving it the larger power ceiling. The Pro-Line 18 Flats 2011 tops out at 115 hp. Keep in mind that maximum ratings are just that — matching the motor to the actual load and usage pattern usually matters more than chasing the ceiling.

How many people can each boat hold?

The Pro-Line 18 Flats 2011 is Coast Guard rated for 5 passengers, while the Pro-Line 21 Sport 2005 is certified for 6. Note that legal capacity and comfortable capacity aren't always the same thing — on a full day out, most experienced boaters aim for about 80% of the rated number to keep things comfortable.

Which boat is wider, and does it affect trailering?

The Pro-Line 21 Sport 2005 measures 101" wide, compared to 96" for the Pro-Line 18 Flats 2011. The US standard-width towing limit is 8’6" (102") in most states — anything over that may need a wide-load permit. Confirm your specific route requirements with each state's DOT.

Which boat has the larger fuel tank — the Pro-Line 18 Flats 2011 or the Pro-Line 21 Sport 2005?

The Pro-Line 18 Flats 2011 has the bigger tank at 27 gallons, versus 7 gallons on the Pro-Line 21 Sport 2005. That 20-gallon difference translates to roughly 60–100 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.

Are the Pro-Line 18 Flats 2011 and Pro-Line 21 Sport 2005 from the same manufacturer?

Yes — both the Pro-Line 18 Flats 2011 and the Pro-Line 21 Sport 2005 are built by Pro-Line. That means shared dealer networks, common parts availability, and consistent build quality across the line. The choice between them is essentially a question of how much boat you need, not which brand you trust.

← Pro-Line 18 Flats 2011 full specs ← Pro-Line 21 Sport 2005 full specs