Larson SEi 180 Fish Series O/B 2005 vs Larson SEi 180 Ski Fish I/O 2007 - Boat Spec Comparison

Q: Which is easier to trailer — the Larson SEi 180 Fish Series O/B 2005 or the Larson SEi 180 Ski Fish I/O 2007?

For trailering, the Larson SEi 180 Ski Fish I/O 2007 has the edge at 265 lbs dry weight versus 1 785 lbs for the Larson SEi 180 Fish Series O/B 2005. 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.

Q: Which boat can handle a bigger outboard?

The Larson SEi 180 Ski Fish I/O 2007 is rated to a maximum of 225 hp, giving it the larger power ceiling. The Larson SEi 180 Fish Series O/B 2005 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.

Q: How many people can each boat hold?

The Larson SEi 180 Fish Series O/B 2005 is Coast Guard rated for 8 passengers, while the Larson SEi 180 Ski Fish I/O 2007 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.

Q: Do these boats require an oversize trailer permit to tow on US highways?

Both the Larson SEi 180 Fish Series O/B 2005 and Larson SEi 180 Ski Fish I/O 2007 share an 7 ft. 9 in beam — meaning both sit right at the 8’6" threshold that most US states use for standard-width loads. In most states you can tow at that width without a special permit, but regulations vary. Always check the rules for your state and any states you'll be passing through before your first long haul.

Q: Which boat has the larger fuel tank — the Larson SEi 180 Fish Series O/B 2005 or the Larson SEi 180 Ski Fish I/O 2007?

The Larson SEi 180 Fish Series O/B 2005 has the bigger tank at 29 gallons, versus 23 gallons on the Larson SEi 180 Ski Fish I/O 2007. That 6-gallon difference translates to roughly 18–30 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.

Q: Are the Larson SEi 180 Fish Series O/B 2005 and Larson SEi 180 Ski Fish I/O 2007 from the same manufacturer?

Yes — both the Larson SEi 180 Fish Series O/B 2005 and the Larson SEi 180 Ski Fish I/O 2007 are built by Larson. 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.

Boat Comparison

Larson SEi 180 Fish Series O/B 2005 vs Larson SEi 180 Ski Fish I/O 2007

Larson

Larson SEi 180 Fish Series O/B 2005

2005

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Larson

Larson SEi 180 Ski Fish I/O 2007

2007

View full specs →

Detailed Evaluation & Buyer Recommendation

Larson SEi 180 Fish Series O/B 2005 vs Larson SEi 180 Ski Fish I/O 2007 — Same Brand, Different Boat

The Larson SEi 180 Fish Series O/B 2005 vs Larson SEi 180 Ski Fish I/O 2007 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.

The power gap is worth calling out. Rated to 225 hp, the Larson SEi 180 Ski Fish I/O 2007 has a 50-hp advantage over the Larson SEi 180 Fish Series O/B 2005'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 Larson SEi 180 Fish Series O/B 2005 carries 29 gallons versus 23 gallons in the Larson SEi 180 Ski Fish I/O 2007. 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 Larson SEi 180 Fish Series O/B 2005 is rated for 8 passengers, while the Larson SEi 180 Ski Fish I/O 2007 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Larson SEi 180 Fish Series O/B 2005 could be the deciding factor.

Bottom line: Choose the Larson SEi 180 Fish Series O/B 2005 if your priority is putting more people on the water — it handles 8 passengers and at 0,0 ft it has the deck room to back that rating up comfortably. The Larson SEi 180 Ski Fish I/O 2007 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.

General Boat Info

MakeLarson

ModelSEi 180 Fish Series O/B

ModelSEi 180 Ski Fish I/O

Model Year2005

Model Year2007

Measurements / Dimensions

Beam7 ft. 9 in

Beam7 ft. 9 in. (2.36 m)

Beam - Meters2.36

Beam - Inches93

Deadrise21℃

Draft [max] - Detail33 in. max

Draft [max] - Detail31 in. (78.7 cm)

Draft [max] - Meters0.84

Draft [max] - Meters0.79

Draft [max] - Inches33

Draft [max] - Inches31

Weight - Detail1,785 lbs. apx

Weight - Detail2,650 lbs. (1,202 kg)

Weight - kg809.66

Weight - kg1202.02

Weight - lbs.1785

Weight - lbs.265

Height [transom]20 in

Height [transom]not available

Length overall - Detail18 ft. 6 in

Length overall - Detail17 ft. 6 in. (5.33 m)

Length overall - Meters5.64

Length overall - Meters5.33

Length overall - Inches222

Length overall - Inches21

Length - Metersnot available

Length - Meters5.33

Length - Feetnot available

Length - Feet17

Length - Inchesnot available

Length - Inches6

Body / Hull

Hull materialFiberglass

Hull typenot available

Hull typeModified Vee

Engine and Drivetrain

Fuel tank capacity - Detail29 gal

Fuel tank capacity - Detail23 gal. (87 l)

Fuel tank capacity - Liters109.78

Fuel tank capacity - Liters87.06

Fuel tank capacity - Gal29

Fuel tank capacity - Gal23

Engine max175 HP

Engine max225 hp

Fuel typenot available

Fuel typeGas

Drive typenot available

Drive typeI/O

Operational Info

Maximum capacity1,880 lbs

Maximum capacity1,100 lbs. (499 kg)

Maximum people8 Persons

Maximum people6

Larson SEi 180 Fish Series O/B 2005 vs Larson SEi 180 Ski Fish I/O 2007 — Common Questions

Which is easier to trailer — the Larson SEi 180 Fish Series O/B 2005 or the Larson SEi 180 Ski Fish I/O 2007?

For trailering, the Larson SEi 180 Ski Fish I/O 2007 has the edge at 265 lbs dry weight versus 1 785 lbs for the Larson SEi 180 Fish Series O/B 2005. 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 Larson SEi 180 Ski Fish I/O 2007 is rated to a maximum of 225 hp, giving it the larger power ceiling. The Larson SEi 180 Fish Series O/B 2005 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 Larson SEi 180 Fish Series O/B 2005 is Coast Guard rated for 8 passengers, while the Larson SEi 180 Ski Fish I/O 2007 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.

Do these boats require an oversize trailer permit to tow on US highways?

Both the Larson SEi 180 Fish Series O/B 2005 and Larson SEi 180 Ski Fish I/O 2007 share an 7 ft. 9 in beam — meaning both sit right at the 8’6" threshold that most US states use for standard-width loads. In most states you can tow at that width without a special permit, but regulations vary. Always check the rules for your state and any states you'll be passing through before your first long haul.

Which boat has the larger fuel tank — the Larson SEi 180 Fish Series O/B 2005 or the Larson SEi 180 Ski Fish I/O 2007?

The Larson SEi 180 Fish Series O/B 2005 has the bigger tank at 29 gallons, versus 23 gallons on the Larson SEi 180 Ski Fish I/O 2007. That 6-gallon difference translates to roughly 18–30 nautical miles of additional range at cruising speed, depending on motor, load, and conditions.

Are the Larson SEi 180 Fish Series O/B 2005 and Larson SEi 180 Ski Fish I/O 2007 from the same manufacturer?

Yes — both the Larson SEi 180 Fish Series O/B 2005 and the Larson SEi 180 Ski Fish I/O 2007 are built by Larson. 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.

← Larson SEi 180 Fish Series O/B 2005 full specs ← Larson SEi 180 Ski Fish I/O 2007 full specs