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What Is a Transom? Where Onboard a Boat is It Located?

Written by J. Harvey / Fact checked by S. Numbers

Where Onboard a Boat is the Transom Located

Boaters tend to inspect their boats’ hulls regularly and some may fail to notice the transom. What is a transom? It’s a flat, rear section of the boat and it’s also called the stern. Some novices have no idea about it.

The outboard motor on small vessels is clamped on a transom. Hence, the life of the boat is where onboard a boat is the transom located. The way you place the engine will involve the whereabouts and the height of the transom.

To learn more about transom and correctly grasp what this part means, read on.

Importance Of Getting The Transom Height

Every boater should know and understand the importance of the correct transom height. It’s an indicator of the size of an outboard motor, which gives power to the boat. So, you can’t separate them as they need to work together.

Major issues will arise from incorrect transom height. A reverse transom is positioned too high, thus, it clashes to the motor bracket and propellers. Moreover, it will be difficult for the propeller to reach the water.

It will also be a hassle to adjust the motor’s trim with a transom that is too high. In this aspect, you can’t create an angle between the boat and the motor. You can’t just dismiss the need to trim the boat until the stern or transom.

This essential step improves the boat’s performance and minimizes waves to give passengers a comfortable ride.

By the same token, it’s not good if the transom is too low. To your regret, the engine will submerge underwater. Of course, it will be impossible to decrease the angle that forms between the boat and the motor.

Since the transom is on the rear section, the weight of the passengers can create unwanted impact too. It will prompt the boat to be in a bow-down position.

You can prevent these unwanted things by knowing how to measure the transom height. When measuring the transom height, you should start from the hull’s bottom at the boat’s center line up to the top of the transom. Then, you can pick the right engine.

Where Onboard Boat is the Transom Located and More About Transom Heights


A propeller operates based on the height of the transom. It also includes attaching the right engine. Refer to the following measurements as directed by the industry’s standard before buying an outboard motor:

Short shaft engines are roughly 15 inches while the long type of engines are 20 inches. A long shaft type needs 25 inches. Some saltwater motors stand up at a height of 30 to 35 inches.

Standard Mounting Of Outboard Motor For Beginners

Every boater has to go through the basics when mounting a motor on a transom. After buying the appropriate engine, the next thing that you have to focus on is the mounting process.

You should know that the anti-ventilation plate of most engines goes parallel with the vessel’s bottom. When you purchase an outboard motor, you will also get mounting holes and brackets. Adjustments can be made as these hardware parts are vertically aligned.

However, adjustments should be done with a lot of thoughts. Ask for advice from a marine engine dealer regarding the boat design before doing so. It may be essential when trailering and you may use an adjustable transom saver.

Lower Mounting May Not be For Beginners

Lower mounting means setting it lower than the basic standard. Unfortunately, adverse effects can’t be avoided. There are several drawbacks like narrowing underwater clearance, increasing drag, excessive spray, and unwanted consequences on fast crafts.

This setup eliminates speed and fuel efficiency. It’s also not favorable when traveling and trailering. When transporting your boat, the motor hangs low and to your dismay, you’ll find some parts that need to be repaired.

What you have to do is test if the motor is at the ideal height. You can do it by putting the engine in idle and trimming the motor by half of the full trim. Then, you can accelerate briskly with precaution.

If the propeller doesn’t ventilate, the motor is mounted too low. Against all odds that were mentioned, a lower mounting level is helpful in some ways. It’s convenient for some fishing boats to have their motors mounted in a lower state.

Yet, it’s still not recommended for beginners to practice lower mounting. They should stick with the standard mounting first.

Higher Mounting, The Most Complex Set-up

Higher mounting should only be left to professionals. If your skills are inadequate, you have to deal with an engine that overheats. It happens if there’s not enough water to cool the engine down.

This set-up, considered as complex, needs support from a sturdy transom. Don’t ever settle for this arrangement if you don’t want to spend on repairs or transom replacement.

The advantage of a high mounting level is giving you a chance to pump up the speed. This will banish all the unpleasant things after putting the mount upwards. However, it can get in the way of the steering capabilities.

There’s always a disadvantage when not adhering to industry standards. That’s why you should never be adventurous on mounting an outboard motor on a transom if you’re a beginner.

Bear in mind that the negative effects can alter the entire operation of your boat. This is a crucial factor so put a lot of thought in every decision that you make.

The Transom’s Angle


Flat transom is naturally zero degrees and its highest angle is 30 degrees. The average angle is around 14 degrees. You have to discover this as it has a pivotal role on a boat’s trimming flexibility.

There are various ways of trimming and a beginner should learn them all. Every way of trimming brings a certain effect on the boat. To obtain the transom’s angle, there’s no need to be a mathematician. Use a ruler to obtain the right numbers.

Transom Maintenance

Transom should be included in the maintenance plan as it bears the motor that gives your boat life. Check the bolts and hardware if they’re all tight. Some boaters have to deal with rotting wood.

This issue can be subdued by solutions like Boat Life Penetrating Epoxy, Nisus Boat Preservative, and Zap Wood Restorer.


Before you get a new outboard motor, you have to look at where onboard a boat is the transom located. Thereby, you can get one that suits your transom. In this way, you don’t have to damage the transom or repair other sections.

You know now that the transom and motor are like a team that works for the same goal. If you’re a beginner, you should be smart to keep practicing the industry standard until you can handle adjustments.

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