May 15

May 15 - May 17

Tom Thornton Jr regatta

PRO-MOD-SO-J CLSES

Mattanawcook Lake

Lincoln, ME

May 16

May 16 - May 17

Harford County Spring Nationals

INB

Bush River

Edgewood, MD

May 16 - May 17

2026 Spring Kickoff

INB-PRO-KPH-MOD-SO-OPC-J CLSES

Lake Minden

Nicolaus, CA

May 16 - May 17

Phantom race Days

MOD-SO-J CLSES

Phantom Lake

Mukwonago, WI

May 22

May 22 - May 25

Boatnik 2026

SE-JET SPRI-OB RR-DRAG

Rogue River

Grants Pass, OR

May 23

May 23 - May 24

Newberg Memorial Weekend Boat Ra...

SO-OPC;R-PRO-KPH-MOD-J CLSES

Willamette River

Newberg , OR

May 23 - May 24

2026 Spring Franklin Regatta

MOD-SO-J CLSES

Justus Lake

Franklin, PA, PA

May 23 - May 24

Cambridge Classic

INB

Hambrooks Bay

Cambridge, MD

May 29

May 29 - May 31

Inboard Driving School

INB

Champions Lake Park

SPRINGFIELD, OH

May 30

May 30

Water Follies Spring Testing

VINTAGE-INB-UNL

Columbia River

Kennewick, WA

May 30 - May 31

Fireside 500

SO;D-J CLSES

Grand Lake

Presque Isle, Michigan, MI

May 30 - May 31

16th Annual Harry Brinkman Memor...

MOD;R-KPH-SO-J CLSES

Lake Clare

Huntington, IN

Jun 2

Jun 2 - Jun 6

Solar Splash: The Intercollegiat...

SE

Clark County Fairgrounds, Champions Park Lake

Springfield, OH

Jun 6

Jun 6 - Jun 7

Hardys Race for the Lake

INB;N

Lake Decatur

Decatur, IL, IL

Jun 6 - Jun 7

Piney Point Rumble on the River

VINTAGE

ST. GEORGES CREEK

PINEY POINT, MD

Jun 6 - Jun 7

Rumble on the River

PRO-KPH

Menominee River

Marinette, WI

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Modified Outboard Menu

Modified Outboard

Modified-Outboard

MOD racers aren't afraid to get their hands dirty - The goal in this category is to pull every last bit of horsepower out of your engine. In Modified Outboard, the engine builder's skill is just as important as the driver's. These boats are easily recognizable by their specially tuned pipes that make them as loud as they are fast. Because engines are constantly being modified to make the absolute most of what the rules allow, the competition is always fierce. Join the ranks of some of the best engine builders in the world, join Modified Outboard Racing.

Whether hydroplane or runabout, Modified classes are defined by the size of their engines (displacement). The numbers in the class names give you the approximate engine size in cubic centimeters. The 250ccMH, or 250 cubic centimeter Mod Hydro, is smaller than the 850ccMH, or 850 cubic centimeter Mod Hydro. Some classes have minimum weights, which increase with engine size. The smaller classes are often a good fit for younger, lighter drivers (14-year-olds may drive 200-250cc Mod classes, for example). The larger classes take considerable skill and experience. Propellers of four blades or less are used, and your prop choice can affect your speed enormously.

Modified Outboard Resources

Modified Outboard Classes