Mariah FS18 Fish & Ski 2006 boat specs
Mariah
Mariah FS18 Fish & Ski 2006
2006
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VS
Mariah G21  2010 boat specs
Mariah
Mariah G21 2010
2010
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Mariah FS18 Fish & Ski 2006 vs Mariah G21 2010 — Same Brand, Different Boat

The Mariah FS18 Fish & Ski 2006 vs Mariah G21 2010 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 — Mariah FS18 Fish & Ski 2006 at 18,0 ft versus Mariah G21 2010 at 20,8 ft. Weight tells a clearer story for trailering families: the Mariah FS18 Fish & Ski 2006 tips the scales at 231 lbs — 192 lbs more than the Mariah G21 2010 at 39 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 270 hp, the Mariah G21 2010 has a 80-hp advantage over the Mariah FS18 Fish & Ski 2006's 190-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Mariah G21 2010 carries 44 gallons versus 22 gallons in the Mariah FS18 Fish & Ski 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 Mariah FS18 Fish & Ski 2006 is rated for 8 passengers, while the Mariah G21 2010 caps at 1. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Mariah FS18 Fish & Ski 2006 could be the deciding factor.

Bottom line: Choose the Mariah FS18 Fish & Ski 2006 if your priority is putting more people on the water — it handles 8 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Mariah G21 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 1 that costs less to run day-to-day.
General Boat Info
MakeMariah
MakeMariah
ModelFS18 Fish & Ski
ModelG21
Model Year2006
Model Year201
Measurements / Dimensions
Beam7 ft. 8 in. (2.3 m)
Beam8 ft. 6 in. (2.6 m)
Beam - Meters2.34
Beam - Meters2.59
Beam - Inches92
Beam - Inches102
Deadrise18℃
Deadrise20℃
Weight - Detail2,310 lbs. (1,048 kg)
Weight - Detail3,300 lbs. (1,497 kg) Maximum: 3,900 lbs. (1,769 kg)
Weight - kg1047.8
Weight - kg1769.01
Weight - lbs.231
Weight - lbs.39
Length - Meters5.5
Length - Meters6.1
Length - Feet18
Length - Feet20.75
Length overall - Detail18 ft. 0 in. (5.5 m)
Length overall - Detail20 ft. 9 in. (6.1 m)
Length overall - Meters5.49
Length overall - Meters6.32
Length overall - Inches216
Length overall - Inches249
Engine and Drivetrain
Fuel tank capacity - Detail22 gal. (83 l)
Fuel tank capacity - Detail44 gal. (167 l)
Fuel tank capacity - Liters83.28
Fuel tank capacity - Liters166.56
Fuel tank capacity - Gal22
Fuel tank capacity - Gal44
Fuel typeGas
Fuel typeGas
Drive typeI/O
Drive typeI/O
Engine max190 hp (142 kW)
Engine max270 hp (201 kW)
Operational Info
Maximum capacity1,250 lbs. (567 kg)
Maximum capacity1,750 lbs. (794 kg)
Maximum people8
Maximum people1
Body / Hull
Hull materialnot available
Hull materialFiberglass
Hull typenot available
Hull typeModified Vee
Performance
Maximum speednot available
Maximum speed41-52 mph

Mariah FS18 Fish & Ski 2006 vs Mariah G21 2010 — Common Questions

Which is the larger boat — the Mariah FS18 Fish & Ski 2006 or the Mariah G21 2010?
The Mariah G21 2010 is the longer of the two at 20,8 feet overall. The Mariah FS18 Fish & Ski 2006 comes in at 18,0 feet, making it roughly 2,8 ft shorter — a meaningful difference in deck room and overall on-water presence.
Which is easier to trailer — the Mariah FS18 Fish & Ski 2006 or the Mariah G21 2010?
For trailering, the Mariah G21 2010 has the edge at 39 lbs dry weight versus 231 lbs for the Mariah FS18 Fish & Ski 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 Mariah G21 2010 is rated to a maximum of 270 hp, giving it the larger power ceiling. The Mariah FS18 Fish & Ski 2006 tops out at 190 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 Mariah FS18 Fish & Ski 2006 is Coast Guard rated for 8 passengers, while the Mariah G21 2010 is certified for 1. 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 Mariah G21 2010 measures 102" wide, compared to 92" for the Mariah FS18 Fish & Ski 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 Mariah FS18 Fish & Ski 2006 or the Mariah G21 2010?
The Mariah G21 2010 has the bigger tank at 44 gallons, versus 22 gallons on the Mariah FS18 Fish & Ski 2006. That 22-gallon difference translates to roughly 66–110 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.
Are the Mariah FS18 Fish & Ski 2006 and Mariah G21 2010 from the same manufacturer?
Yes — both the Mariah FS18 Fish & Ski 2006 and the Mariah G21 2010 are built by Mariah. 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.