Inboard vs Outboard Saltwater? Which One Is Better For You

One of the most important issues to address when purchasing a boat for usage in coastal waters is whether outboard or inboard motors are preferable for saltwater boats. Let’s take a look at the advantages and disadvantages of each type, thus you can choose a suitable motor for you.

Inboard Saltwater Motor

High-performance engines converted for maritime usage are known as inboard motors. They may attach in the middle of your boat (direct drive systems) or stow inside the transom (rear drive systems) (V-drive systems). The propulsion system and prop are integrated into the hull in both situations.

Inboard engines provide advantages due to their automotive heritage and more complicated design – but at a similar price.

  • Excellent fuel efficiency
  • Quiet operation
  • Increased longevity – usually beyond 6,000 hours
  • Superior torque and power

Wakeboarding and waterskiing are popular water activities, especially with several skiers, since inboard engines provide greater wake control, more towing power, and a clean transom for tow lines. Cutting through large ocean waves is also easier with a lower center of gravity.

Unfortunately there are some downsides for boats with inboard engines, such as:

  • Reduced interior space
  • Higher upfront cost
  • Labor-intensive maintenance
  • Significantly more complex repairs
  • Full boat winterization required

Outboard Saltwater Motor

Mercury outboard motors are completely self-contained units that attach to the transom’s outside. Outboard motors can be controlled through a dashboard console or a handle linked directly to the motor, depending on your preference.

There are several reasons to opt for an outboard engine:

  • Full portability
  • Far easier maintenance – just tilt
  • Simple winterizing procedure and space-saving storage
  • A Significantly lower price tag
  • Extra interior space
  • Higher potential top speed

Outboard motors are preferred by fishermen, speedboat owners, and party captains because of their rapid handling, tight turn ratio, and low-speed maneuverability. You may securely tilt the prop out of the water at any moment while boating in shallow seas.

Besides the above mentioned advantages, outboards lack the entire torque needed to operate bigger boats, despite their higher power to weight ratio. To some extent, enthusiasts get around this by installing a second motor. It’s not uncommon to see three or four motors decorating the transoms of today’s bigger center consoles.

What are the Key Differences Between Inboard and Outboard Motors?

inboard vs outboard saltwater

Inboard family boats nearly generally have a sterndrive (also known as an inboard/outboard or I/O) powertrain, which combines an automotive-style engine located inside the boat with a steerable and trimmable drive unit mounted on the stern (rear). A specialist watersports tow boat, with an inboard engine operating a propeller beneath the boat and steering control given by a rudder, would be an exception.

Sterndrives range in power from 200 to 430 horsepower, however many pre-owned tiny runabouts may be equipped with a 130-horsepower sterndrive that is no longer in production. A specialized marine engine that is mounted directly to the stern of a boat is known as an outboard motor.

Outboards range in power from 2-horsepower kickers to 600-horsepower monsters, but the normal range for family boating is 90-300 horsepower. Outboard motors are gaining favor on bigger cabin cruisers and day boats that were previously only fitted with inboard engines as outboard motors have gotten more powerful. These can be equipped with three or four outboard engines that, when combined, produce more power than the most powerful pair of sterndrive engines available, resulting in performance that was formerly unheard of.

Initial Cost Comparison

Making a pricing comparison based on horsepower—a 250-horsepower outboard against a 250-horsepower sterndrive in the same boat—seems obvious, but it’s preferable to do it based on performance.

In this case, a 200-horsepower outboard will generally match the performance of a 250-horsepower sterndrive simply because the outboard is lighter and is better positioned behind the boat rather than within it. As you travel up and down the horsepower spectrum, this rule of thumb stays true. However, even with fewer horsepower, an outboard-powered boat would typically cost 2 to 4% more than a sterndrive-powered boat.

Inboard vs. Outboard Maintenance Costs & Ownership

An outboard motor will often provide higher fuel efficiency than a sterndrive due to its less weight and more efficient construction. Both will require comparable yearly maintenance, with the exception that most sterndrive engines’ cooling systems will need to be flushed with antifreeze solution in cold areas, which is normally done by a marine service shop.

Because an outboard is self-draining, many owners may perform their own off-season maintenance.

Sterndrives used to have a reputation for being more prone to corrosion in salt water, but current engines and outdrives have greatly improved corrosion resistance, and many may be installed with a closed cooling system that keeps the majority of saltwater out of the engine.

Most sterndrives, on the other hand, cannot be totally tilted out of the water, but most outboards can clear the water when fully inclined. If the boat is tied or moored in saltwater full time, this is a benefit for the outboard since it inhibits marine development and corrosion on the drive.

An outboard is easier to maintain than an inboard since the whole engine is located outside the boat. You may just stand next to the outboard while the boat is on a trailer.

Working on the inboard engine necessitates working under an engine hatch, frequently in close quarters. When an outboard is broken or just worn out, repowering the boat with a new outboard is rather simple. An inboard boat may also be repowered, although this is a more difficult job.


Here’s what will probably make or break your choice when you are deciding between inboard and outboard motors

  • Favorite water activity
  • Boat size
  • Desired maneuverability
  • Boating frequency
  • Local year-round climate

The outboards make a lot of sense as a long-term investment in fishing, family day sailing, and weekend adventures, especially given the price difference. However, if you’re going fishing and cruising at the same time, a diesel inboard with a cabin bulkhead and genset like the Justified makes a lot of sense, especially if you want to cruise at trawler speeds. So, the ultimate winner is determined by your boating preferences.

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