Seaswirl 1851 Dual Console O/B 2006 boat specs
Seaswirl
Seaswirl 1851 Dual Console O/B 2006
2006
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VS
Seaswirl 21 Center Console 2008 boat specs
Seaswirl
Seaswirl 21 Center Console 2008
2008
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Seaswirl 1851 Dual Console O/B 2006 vs Seaswirl 21 Center Console 2008 — Same Brand, Different Boat

The Seaswirl 1851 Dual Console O/B 2006 vs Seaswirl 21 Center Console 2008 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.

On paper these two are close siblings in the size department — Seaswirl 1851 Dual Console O/B 2006 at 18,0 ft versus Seaswirl 21 Center Console 2008 at 21,0 ft. Weight tells a clearer story for trailering families: the Seaswirl 1851 Dual Console O/B 2006 tips the scales at 255 lbs — 228 lbs more than the Seaswirl 21 Center Console 2008 at 27 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.

The power gap is worth calling out. Rated to 250 hp, the Seaswirl 21 Center Console 2008 has a 75-hp advantage over the Seaswirl 1851 Dual Console O/B 2006's 175-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Seaswirl 21 Center Console 2008 carries 105 gallons versus 62 gallons in the Seaswirl 1851 Dual Console O/B 2006. 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 Seaswirl 21 Center Console 2008 is rated for 6 passengers, while the Seaswirl 1851 Dual Console O/B 2006 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Seaswirl 21 Center Console 2008 could be the deciding factor.

Bottom line: Choose the Seaswirl 21 Center Console 2008 if your priority is putting more people on the water — it handles 6 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The Seaswirl 1851 Dual Console O/B 2006 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
MakeSeaswirl
MakeSeaswirl
Model1851 Dual Console O/B
Model21 Center Console
Model Year2006
Model Year2008
Measurements / Dimensions
Beam90 in. (2.29 m)
Beam8 ft. 6 in
Beam - Meters2.29
Beam - Meters2.59
Beam - Inches9
Beam - Inches102
Bridge clearance - Detail51 in. (1.30 m)
Bridge clearance - Detailnot available
Bridge clearance - Meters1.3
Bridge clearance - Metersnot available
Bridge clearance - Inches51
Bridge clearance - Inchesnot available
Deadrise20℃
Deadrise22℃
Draft [drive up] - Detail14 in. (.35 m)
Draft [drive up] - Detailnot available
Draft [drive up] meters0.36
Draft [drive up] metersnot available
Draft [drive up] inches14
Draft [drive up] inchesnot available
Draft [max] - Detail30 in. (.76 m)
Draft [max] - Detail16 in
Draft [max] - Meters0.76
Draft [max] - Meters0.41
Draft [max] - Inches3
Draft [max] - Inches16
Weight - Detailw/ standard engine: 2,550 lbs. (1,157 kg)
Weight - Detail2,700 lbs. (w/o power)
Weight - kg1156.66
Weight - kg1224.7
Weight - lbs.255
Weight - lbs.27
Length - Meters5.64
Length - Metersnot available
Length - Feet18
Length - Feet21
Length - Inches6
Length - Inchesnot available
Length overall - Detail18 ft. 6 in. (5.64 m)
Length overall - Detail21 ft. 0 in
Length overall - Meters5.64
Length overall - Meters6.4
Length overall - Inches222
Length overall - Inches252
Engine and Drivetrain
Fuel tank capacity - Detail62 gal. (235 l)
Fuel tank capacity - Detail105 gal
Fuel tank capacity - Liters234.7
Fuel tank capacity - Liters397.47
Fuel tank capacity - Gal62
Fuel tank capacity - Gal105
Fuel typeGas
Fuel typenot available
Drive typeOutboard
Drive typeOutboard
Engine max175 hp (130 kw) Standard: 115 hp (86 kw)
Engine max250 hp
Engine/s standardnot available
Engine/s standard150 hp
Operational Info
Maximum capacity1,900 lbs. (862 kg)
Maximum capacitynot available
Body / Hull
Hull materialnot available
Hull materialFiberglass
Hull typenot available
Hull typeDeep Vee

Seaswirl 1851 Dual Console O/B 2006 vs Seaswirl 21 Center Console 2008 — Common Questions

Which is the larger boat — the Seaswirl 1851 Dual Console O/B 2006 or the Seaswirl 21 Center Console 2008?
The Seaswirl 21 Center Console 2008 is the longer of the two at 21,0 feet overall. The Seaswirl 1851 Dual Console O/B 2006 comes in at 18,0 feet, making it roughly 3,0 ft shorter — a meaningful difference in deck room and overall on-water presence.
Which is easier to trailer — the Seaswirl 1851 Dual Console O/B 2006 or the Seaswirl 21 Center Console 2008?
For trailering, the Seaswirl 21 Center Console 2008 has the edge at 27 lbs dry weight versus 255 lbs for the Seaswirl 1851 Dual Console O/B 2006. 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 Seaswirl 21 Center Console 2008 is rated to a maximum of 250 hp, giving it the larger power ceiling. The Seaswirl 1851 Dual Console O/B 2006 tops out at 175 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 Seaswirl 1851 Dual Console O/B 2006 is Coast Guard rated for 5 passengers, while the Seaswirl 21 Center Console 2008 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 Seaswirl 21 Center Console 2008 measures 102" wide, compared to 9" for the Seaswirl 1851 Dual Console O/B 2006. 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 Seaswirl 1851 Dual Console O/B 2006 or the Seaswirl 21 Center Console 2008?
The Seaswirl 21 Center Console 2008 has the bigger tank at 105 gallons, versus 62 gallons on the Seaswirl 1851 Dual Console O/B 2006. That 43-gallon difference translates to roughly 129–215 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.
Are the Seaswirl 1851 Dual Console O/B 2006 and Seaswirl 21 Center Console 2008 from the same manufacturer?
Yes — both the Seaswirl 1851 Dual Console O/B 2006 and the Seaswirl 21 Center Console 2008 are built by Seaswirl. 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.