Mariah FS20 Fish & Ski 2007 boat specs
Mariah
Mariah FS20 Fish & Ski 2007
2007
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VS
Mariah R18.9  2009 boat specs
Mariah
Mariah R18.9 2009
2009
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Mariah FS20 Fish & Ski 2007 vs Mariah R18.9 2009 — Same Brand, Different Boat

The Mariah FS20 Fish & Ski 2007 vs Mariah R18.9 2009 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.

Size is the most obvious dividing line here. The Mariah R18.9 2009 measures 18,0 feet overall (2009), giving it roughly 16,0 additional feet of deck space compared to the Mariah FS20 Fish & Ski 2007 at 2,0 feet (2007). At 33 lbs and 33 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.

The power gap is worth calling out. Rated to 260 hp, the Mariah FS20 Fish & Ski 2007 has a 35-hp advantage over the Mariah R18.9 2009's 225-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 FS20 Fish & Ski 2007 carries 38 gallons versus 22 gallons in the Mariah R18.9 2009. 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 R18.9 2009 is rated for 8 passengers, while the Mariah FS20 Fish & Ski 2007 caps at 1. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Mariah R18.9 2009 could be the deciding factor.

At this size, power-to-weight ratio matters more than outright horsepower. The Mariah R18.9 2009 comes in at 0 lbs per hp versus 0 lbs per hp for the Mariah FS20 Fish & Ski 2007. The lower the ratio the more explosive the acceleration — meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.

The Mariah R18.9 2009 has a documented top speed of 40 mph. Speed data wasn't available for the other model.

Bottom line: Choose the Mariah R18.9 2009 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 FS20 Fish & Ski 2007 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
ModelFS20 Fish & Ski
ModelR18.9
Model Year2007
Model Year2009
Measurements / Dimensions
Beam8 ft. 2 in. (2.5 m)
Beam7 ft. 10 in. (2.4 m)
Beam - Meters2.49
Beam - Meters2.39
Beam - Inches98
Beam - Inches94
Deadrise19℃
Deadrise18℃
Weight - Detail3,300 lbs. (1,498 kg)
Weight - Detail2,800 lbs. (1,270 kg) Maximum: 3,300 lbs. (1,497 kg)
Weight - kg1496.85
Weight - kg1496.85
Weight - lbs.33
Weight - lbs.33
Length - Meters6.1
Length - Meters5.5
Length - Feet2
Length - Feet18
Length overall - Detail20 ft. 0 in. (6.1 m)
Length overall - Detail18 ft. 4 in. (5.5 m)
Length overall - Meters6.1
Length overall - Meters5.59
Length overall - Inches24
Length overall - Inches22
Length - Inchesnot available
Length - Inches4
Body / Hull
Hull materialFiberglass
Hull materialFiberglass
Hull typenot available
Hull typeModified Vee
Engine and Drivetrain
Fuel tank capacity - Detail38 gal. (144 l)
Fuel tank capacity - Detail22 gal. (83 l)
Fuel tank capacity - Liters143.85
Fuel tank capacity - Liters83.28
Fuel tank capacity - Gal38
Fuel tank capacity - Gal22
Fuel typeGas
Fuel typeGas
Drive typeI/O
Drive typeI/O
Engine max260 hp (194 kW)
Engine max225 hp (168 kW)
Operational Info
Maximum capacityPerson: 1,590 lbs. (721 kg) Total: 3,550 lbs. (1,612 kg)
Maximum capacity1,250 lbs. (567 kg)
Maximum people1
Maximum people8
Performance
Maximum speednot available
Maximum speed40-45 mph

Mariah FS20 Fish & Ski 2007 vs Mariah R18.9 2009 — Common Questions

Which is the larger boat — the Mariah FS20 Fish & Ski 2007 or the Mariah R18.9 2009?
The Mariah R18.9 2009 is the longer of the two at 18,0 feet overall. The Mariah FS20 Fish & Ski 2007 comes in at 2,0 feet, making it roughly 16,0 ft shorter — a meaningful difference in deck room and overall on-water presence.
Which is easier to trailer — the Mariah FS20 Fish & Ski 2007 or the Mariah R18.9 2009?
For trailering, the Mariah R18.9 2009 has the edge at 33 lbs dry weight versus 33 lbs for the Mariah FS20 Fish & Ski 2007. 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 FS20 Fish & Ski 2007 is rated to a maximum of 260 hp, giving it the larger power ceiling. The Mariah R18.9 2009 tops out at 225 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 FS20 Fish & Ski 2007 is Coast Guard rated for 1 passengers, while the Mariah R18.9 2009 is certified for 8. 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 better power-to-weight ratio?
The Mariah R18.9 2009 has a better power-to-weight ratio at 0 lbs per hp compared to 0 lbs per hp for the Mariah FS20 Fish & Ski 2007. A lower number means quicker acceleration and faster time to plane — the number that actually matters most on short, sporty boats like these.
Which boat is wider, and does it affect trailering?
The Mariah FS20 Fish & Ski 2007 measures 98" wide, compared to 94" for the Mariah R18.9 2009. 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 FS20 Fish & Ski 2007 or the Mariah R18.9 2009?
The Mariah FS20 Fish & Ski 2007 has the bigger tank at 38 gallons, versus 22 gallons on the Mariah R18.9 2009. That 16-gallon difference translates to roughly 48–80 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.
Are the Mariah FS20 Fish & Ski 2007 and Mariah R18.9 2009 from the same manufacturer?
Yes — both the Mariah FS20 Fish & Ski 2007 and the Mariah R18.9 2009 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.