ThunderJet Alexis OB Offshore - 21 ft. 2008 boat specs
ThunderJet
ThunderJet Alexis OB Offshore - 21 ft. 2008
2008
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VS
ThunderJet Havasu 2010 boat specs
ThunderJet
ThunderJet Havasu 2010
2010
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ThunderJet Alexis OB Offshore - 21 ft. 2008 vs ThunderJet Havasu 2010 — Which Modified Vee Fits Your Needs?

When two boats share the same hull type — in this case both the ThunderJet Alexis OB Offshore - 21 ft. 2008 and the ThunderJet Havasu 2010 are modified vee designs with aluminum 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 power gap is worth calling out. Rated to 500 hp, the ThunderJet Alexis OB Offshore - 21 ft. 2008 has a 475-hp advantage over the ThunderJet Havasu 2010's 25-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads — 5 gal and 5 gal — so range won't be a tiebreaker here.

Both boats are rated for 6 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 ThunderJet Alexis OB Offshore - 21 ft. 2008 at 21,0 ft is the right call if deck space, comfort, and entertaining are top of your list. The ThunderJet Havasu 2010 at 2,0 ft wins on trailering ease, likely lower purchase price, and simpler docking — a solid choice for a buyer who wants more boat for less money.
General Boat Info
MakeThunderJet
MakeThunderJet
ModelAlexis OB Offshore - 21 ft
ModelHavasu
Model Year2008
Model Year201
Measurements / Dimensions
Beam102 in
Beam90 in
Beam - Meters2.59
Beam - Meters2.29
Beam - Inches102
Beam - Inches9
Width [transom] - Detail40 in
Width [transom] - Detail72 in
Height - DetailSides: 40 in
Height - Detailnot available
Height - Meters1.02
Height - Metersnot available
Height - Inches4
Height - Inchesnot available
Length - Feet21
Length - Feet2
Length overall - Detail21 ft. 0 in
Length overall - Detail20 ft. 0 in
Length overall - Meters6.4
Length overall - Meters6.1
Length overall - Inches252
Length overall - Inches24
Deadrisenot available
Deadrise12° Entry: 40° Engine: 14°
Weight - Detailnot available
Weight - Detail2,600 lbs
Weight - kgnot available
Weight - kg1179.34
Weight - lbs.not available
Weight - lbs.26
Height [transom]not available
Height [transom]31 in
Body / Hull
Hull materialAluminum
Hull materialAluminum
Hull thickness0.190 in
Hull thicknessnot available
Hull typeModified Vee
Hull typeModified Vee
Engine and Drivetrain
Fuel tank capacity - Detail50 gal
Fuel tank capacity - Detail50 gal
Fuel tank capacity - Liters189.27
Fuel tank capacity - Liters189.27
Fuel tank capacity - Gal5
Fuel tank capacity - Gal5
Fuel typeGas
Fuel typeGas
Drive typeOutboard
Drive typeInboard
Engine max500 hp
Engine maxnot available
Horsepowernot available
Horsepower25

ThunderJet Alexis OB Offshore - 21 ft. 2008 vs ThunderJet Havasu 2010 — Common Questions

Which is the larger boat — the ThunderJet Alexis OB Offshore - 21 ft. 2008 or the ThunderJet Havasu 2010?
The ThunderJet Alexis OB Offshore - 21 ft. 2008 is the longer of the two at 21,0 feet overall. The ThunderJet Havasu 2010 comes in at 2,0 feet, making it roughly 19,0 ft shorter — a meaningful difference in deck room and overall on-water presence.
Which boat can handle a bigger outboard?
The ThunderJet Alexis OB Offshore - 21 ft. 2008 is rated to a maximum of 500 hp, giving it the larger power ceiling. The ThunderJet Havasu 2010 tops out at 25 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 ThunderJet Alexis OB Offshore - 21 ft. 2008 is Coast Guard rated for 6 passengers, while the ThunderJet Havasu 2010 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 ThunderJet Alexis OB Offshore - 21 ft. 2008 measures 102" wide, compared to 9" for the ThunderJet Havasu 2010. 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.
How do the fuel tanks compare on the ThunderJet Alexis OB Offshore - 21 ft. 2008 and ThunderJet Havasu 2010?
Both boats carry similar fuel loads — 5 gallons and 5 gallons respectively. Range will depend heavily on motor choice, throttle usage, and whether you're on flat lake water or coastal chop.
Are the ThunderJet Alexis OB Offshore - 21 ft. 2008 and ThunderJet Havasu 2010 from the same manufacturer?
Yes — both the ThunderJet Alexis OB Offshore - 21 ft. 2008 and the ThunderJet Havasu 2010 are built by ThunderJet. 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.