Most likely, one of the main reasons you purchased or are interested in a flat bottomed Jon boat is so you can get into all those places a regular keel style boat can’t. Maybe it’s a river inlet, or shallow fishing areas or just wanting to be able to get up to shore without bottoming out. But the question remains… how shallow can a Jon boat run?
Many boaters report being able to easily drive in water from 1-2 feet with their flat bottom Jon boats.
Jon boats are specifically built to operate in shallow water, but how shallow is going to depend on two main things: your hull draft and your motor shaft length.
What Is Draft?
Draft is simply how low your boat goes below the waterline. To determine it, you measure from the waterline to the lowest part of the hull or keel. This will give you your hull draft.
It’s vital that you know what the draft is for you boat, or you’ll quickly find yourself in trouble. If you use a depth finder while fishing, it’s a great tool because you have actual data about the water’s depth and can use it in your navigation.
If you aren’t careful, you can bottom out or foul up your motor’s prop with underwater vegetation or debris. Or you might even cause greater damage by hitting a rock or tree stump under there and bend the shaft or ruin the entire motor.
How Do Different Types Of Jon Boats Draft?
For the most part there are two types of Jon boats; V-hull and flat bottom. There are also hybrids or utility boats which are a combination, but for our purposes we are only going to concentrate on the two distinct styles.
The V-Hull
A V-hull is when the bottom of the boat comes down in a straight line to the keel and makes a shape similar to a “V’ or a wedge. It’s closer in style to a traditional keel style boat.
- V-hulls are usually more stable in waves and can cut through them easily.
- With its higher sides, it can be driven faster without taking on water.
- V-hulls tend to weigh more and require more horsepower and fuel to push.
- More ideal for larger bodies of water due to shape and maneuverability.
- Going to require more draft for safe clearance than a flat bottom boat.
The Flat Bottom
Instead of coming down at an angle to a keel, the flat bottom boat has a smooth, flat shape that rides over the water.
- It’s more stable in calm water, especially with smaller boat lengths.
- Lighter and requires a smaller motor than other style of boats.
- Uses less fuel because it glides over the water instead of pushing through it.
- Easier to stand up and move around with less rocking than a V-hull.
- It’s also easier to pull up on a riverbank or to traverse the shallows or rocky waters without bottoming out.
- Requires far less draft than a V-hull for safe underwater clearance.
How Shallow Can A Jon Boat Really Go?
Every situation is going to be a little bit different but boaters report being able to easily drive in water from 1-2 feet with their flat bottom Jon boats and engines engaged in the standard position.
A V-hull is obviously going to need more of a draft, and could certainly require 2-3 feet of clearance underwater to be able to safely maneuver.
Other Jon boaters say that their flat bottom will glide through six inches of water once they pull up that motor. Some will use it in the upright position, skimming the top of the water, or turn it off completely and simply oar or paddle through the shallows. This practice also limits the amount of underwater muck and debris that can get churned up.
Motor Shaft Length
The length of your motor shaft is one of the major factors in how shallow you can go.
The rule of thumb for choosing a shaft length for your Jon boat is usually measuring the distance from the top of the stern to the bottom of the middle of the hull. You want your shaft length to be about that long.
Being off by an inch isn’t going to be an issue, but you don’t want to go much further because you will then find you lose the ability to glide through shallow waters. If your motor is several inches bellow the hull, you are limiting your clearance.
Motor For Flat Bottom Versus Standard Hulls
The standard shaft length for a trolling motor is 42 inches. However, most Jon boats require a shaft length much shorter than that in order to take full advantage of its ability to travel in shallow water. So you are going to need to find an adjustable motor or a non-standard issue motor.
Other boaters have solved the issue by mounting their motor higher on the transom to make the amount of shaft in the water shorter.
It’s Not Always The Bottom That Will Get You
In certain waters, especially near the shore or in a slow moving river, your biggest concern actually isn’t hitting the water, but tying up in underwater grasses or debris coming up from the bottom.
You could easily be in three or feet of water, but vegetation could be much longer and foul up your prop causing it to seize or overheat.
You can purchase weedless props which will help you not get caught up in underwater vegetation. You can easily change out the standard issue for specially made props such as the MinnKota MKP series or other brands. The blades are specifically shaped in order to cut through plant life by pushing it away.
How Can I Fight Shallow Drafts And Increase Stability?
There are many affordable ways ingenious boaters have found to stabilize their flat bottom boats.
Some have added lengths of PVC pipes attached to the sides to increase stability for prices well under $150. Some people have even added pool noodles to provide some additional stability and ride higher in the water.
Other inventive boaters have added pontoons on the sides of their boats, in an almost catamaran or outrigger style. With the pontoons attached, boat rock is greatly minimized and stability increased.
Materials can range from actual pontoons to Styrofoam fishing floaters or large pieces of foam. Some boaters have simply used containers filled with spray foam with positive results.
As always, be careful about damaging the structural integrity of your boat by making alterations and additions. Also, consider a test run in calm waters before you venture out into the chop.
Related Questions
How Big A Motor Should I Get For My Jon Boat?
You don’t need to get a huge motor for your Jon boat. Most likely you are not going to need a large amount of power or speed. In fact, 8 to 20 HP will be plenty of power for you, especially if you are staying on calmer lakes and rivers. See our Max Horsepower for Jon Boats article for more detailed information about specific power requirements for different boat sizes.
Look at your boat’s capacity plate and usually you’ll be fine with about 50 percent of the maximum. For example if your capacity is 40 HP, you’ll be fine with 20. It will give you plenty of power and maneuverability, even in rough water.
Also pay attention to the weight of the motor. You don’t want a piece of heavy, cumbersome machinery that drives the back of your boat down or is unwieldy. Remember, in order to take advantage of the boat’s ability to maneuver in very shallow water, you are most likely going to need to flip that engine up. You don’t want to have to deal with a massive amount of weight and power in a motor that you really don’t need.
You do however need to make sure that you have enough power to be able to “plane” your Jon boat, or lift the front up as you pick up speed. You want this because it is more stable and allows you to handle the boat better.
Should I Get A Bow Or Stern Motor?
If you are going to be traveling into deep water or an area where it gets a bit rough, you are going to want to stay with a stern motor to be able to maneuver though the chop.
Yet in calmer waters and the shallows, most boaters find that a bow mount is easier to control. Some boaters will even add a bow motor they can easily pull up in addition to their stern mounted motor.
In certain conditions a bow motor can give you more control and power because it’s pulling and not pushing the boat. Because of the motor positioning, the pivot point of your boat happens from the front where your power is, instead of coming from the back and requiring the entire boat to turn first. You can maneuver quicker and have better response from your boat.
While some smaller trolling motors will simply clamp to the bow, depending on what size and style you purchase, you might need to add some sort of support structure to the front of your boat. Make sure it is well secured and sturdy. Also be careful not to ruin the integrity of the boat with your handiwork. Make sure to reinforce any screw holes and seal them.
Some boaters complain about having to get to the bow to control their motors, but there are several after market devices that can allow you control it from other parts of the boat, including hand controls, foot pedals and even remote control wireless systems you can easily install.
