Allison XB-21 ProSport S.U.B. 2010 boat specs
Allison
Allison XB-21 ProSport S.U.B. 2010
2010
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VS
Allison XS-2003 Grandsport Elite 2012 boat specs
Allison
Allison XS-2003 Grandsport Elite 2012
2012
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Allison XB-21 ProSport S.U.B. 2010 vs Allison XS-2003 Grandsport Elite 2012 — A Close Look at Two Modified Vees

When two boats share the same hull type — in this case both the Allison XB-21 ProSport S.U.B. 2010 and the Allison XS-2003 Grandsport Elite 2012 are modified vee designs with composite construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?

The Allison XS-2003 Grandsport Elite 2012 tops out at 450 hp. Engine specs for the Allison XB-21 ProSport S.U.B. 2010 aren't listed — confirm with a dealer before selecting an outboard.Fuel capacity breaks the other way: the Allison XB-21 ProSport S.U.B. 2010 carries 36 gallons versus 3 gallons in the Allison XS-2003 Grandsport Elite 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

Both boats are rated for 5 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.

Bottom line: The Allison XB-21 ProSport S.U.B. 2010 and Allison XS-2003 Grandsport Elite 2012 are closely matched on the specs that matter most. Test-ride both on the water you actually use, check current dealer pricing, and factor in long-term service access before you sign.
General Boat Info
MakeAllison
MakeAllison
ModelXB-21 ProSport S.U.B
ModelXS-2003 Grandsport Elite
Model Year201
Model Year2012
Measurements / Dimensions
Length - Feet21
Length - Feet20.25
Beamnot available
Beam87 in
Beam - Metersnot available
Beam - Meters2.21
Beam - Inchesnot available
Beam - Inches87
Depth - Detailnot available
Depth - DetailMolded: 38 in
Depth - Centimetersnot available
Depth - Centimeters96.52
Depth - Inchesnot available
Depth - Inches38
Weight - Detailnot available
Weight - Detail940-980 lbs
Weight - kgnot available
Weight - kg444.52
Weight - lbs.not available
Weight - lbs.98
Length overall - Detailnot available
Length overall - Detail20 ft. 3 in. Centerline: 19 ft
Length overall - Metersnot available
Length overall - Meters6.17
Length overall - Inchesnot available
Length overall - Inches243
Body / Hull
Hull materialComposite
Hull materialComposite
Hull typeModified Vee
Hull typeModified Vee
Engine and Drivetrain
Fuel tank capacity - Detail36+ gal
Fuel tank capacity - Detail30 gal
Fuel tank capacity - Liters136.27
Fuel tank capacity - Liters113.56
Fuel tank capacity - Gal36
Fuel tank capacity - Gal3
Fuel typeGas
Fuel typeGas
Drive typeOutboard
Drive typeOutboard
Horsepowernot available
Horsepower90-150 hp
Engine maxnot available
Engine maxMax Engine Weight: 450 lbs
Operational Info
Maximum people5
Maximum people5
Trailer Info
Trailer - Detailnot available
Trailer - DetailAllison deluxe tube frame; disc brakes with auto electric back-up release

Allison XB-21 ProSport S.U.B. 2010 vs Allison XS-2003 Grandsport Elite 2012 — Common Questions

Which is the larger boat — the Allison XB-21 ProSport S.U.B. 2010 or the Allison XS-2003 Grandsport Elite 2012?
The Allison XB-21 ProSport S.U.B. 2010 is the longer of the two at 21,0 feet overall. The Allison XS-2003 Grandsport Elite 2012 comes in at 20,3 feet, making it roughly 0,8 ft shorter — a meaningful difference in deck room and overall on-water presence.
What is the maximum horsepower rating for these boats?
The Allison XS-2003 Grandsport Elite 2012 has a documented max rating of 450 hp. Engine specifications for the Allison XB-21 ProSport S.U.B. 2010 were not available in our database — check the OEM spec sheet or manufacturer's website for confirmation.
How many people can each boat hold?
The Allison XB-21 ProSport S.U.B. 2010 is Coast Guard rated for 5 passengers, while the Allison XS-2003 Grandsport Elite 2012 is certified for 5. 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 has the larger fuel tank — the Allison XB-21 ProSport S.U.B. 2010 or the Allison XS-2003 Grandsport Elite 2012?
The Allison XB-21 ProSport S.U.B. 2010 has the bigger tank at 36 gallons, versus 3 gallons on the Allison XS-2003 Grandsport Elite 2012. That 33-gallon difference translates to roughly 99–165 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.
Are the Allison XB-21 ProSport S.U.B. 2010 and Allison XS-2003 Grandsport Elite 2012 from the same manufacturer?
Yes — both the Allison XB-21 ProSport S.U.B. 2010 and the Allison XS-2003 Grandsport Elite 2012 are built by Allison. 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.