A good aluminum boat can bring many years of joyous fishing on the water. They can be cheap, very stable, and age really well, making them ideal for fishing if properly maintained.

However, they are generally small, so it can be a bit of a chore stumbling around when trying to make that perfect cast.

This is where a solid casting deck comes in; these decks create a good open space to allow you to cast unhindered. It will also raise you a bit higher above the water level to give you a better view of your surroundings.

There are many different styles of aluminum boats, however in this article we will focus on a typical Jon boat. These boats are often modified (see some stunning Jon boat mods) in many ways to suit the skipper’s preference. Luckily the tips presented in this article are quite universal and should apply to most aluminum boats.

Read on to see how to build a casting deck in an aluminum boat. It will be raised in order to offer a functional casting platform.  I will describe how to measure the size of your deck, cut out compartments for storage, how to build the frame so that it is light as well as strong and how to cover the deck with a marine grade carpet.

How to build a casting deck in an aluminium boat

1. Measure your boat

Before you get started you will need to measure your boat so you know how big the raised casting deck will be. These dimensions can be very general as you just need to get a loose idea of the quantity of materials you will need.

The main thing you are trying to determine is how much plywood you will need to create the raised deck.

To do this, measure the widest point of where your casting deck will be. This will most likely be the width of the front bench or middle bench depending on how big you want your casting deck to be.

Then measure from this seat to the front of the boat.

Check what standard sizes of plywood are available at your local hardware store – ideally you will want one continuous section of plywood as any seam will be a weak point as well as a point where water can seep through.

2. Determine the shape of the casting deck

Next you will want to get the exact shape of the deck.

The easiest way to do this is to get a large piece of cardboard.

Cut out a piece of carboard that is slightly smaller than the deck area that can easily fit inside the boat.

The easiest way to do this is measure the length of the front bench and the bow, then measure the distance from the front of the boat to the seat. Use these to draw a trapezoid on the carboard and cut it out.

It won’t matter is there is a gap on the sides as these will be filled, in fact it is better if there is a gap!

Place the cardboard into the boat and begin filling in the open gap with smaller pieces of loose cardboard. Once you are happy with the fit you can tape these sections to the large piece of cardboard to make an accurate template.

This method also allows you to make a snug fit around any structural components on the boat.

Once the template is done and you are happy with the fit you can move on to the next step.

The video below will give you a good idea of how to create the cardboard cutout (see more videos like this on the excellent DIY Crab Channel).

3. Cut the deck material

Place the template onto the plywood sheet and draw out the shape of the deck.

Handy Hint: It is important to note that you should never use pressure treated wood as it will corrode your aluminum due to galvanic corrosion.

There is a good chance that a standard sheet of plywood will be just a tiny bit too small.

If this is the case mark out as much as you can, the remainder can be filled in with some left-over plywood later. You can now begin cutting the board, use a jigsaw so that you can create relatively smooth cut.

Try keeping the jigsaw about ¼ to 3/8 inches inside the line; this is to allow some clearance for the carpet. Once the board is cut you can use an orbital sander to smooth out any rough-cut areas.

If you are planning on mounting a trawling motor onto the front of your boat, you will want to create small cubby hole for the battery to keep it safe and dry.

Measure out the size of the battery and add a little extra on this dimension to allow you to easily reach inside and pull the battery out.

Draw a center line on the deck and use this to mark out the location for the hatch. Then using a drill bit whose diameter is larger than the jigsaw blade, drill a hole on each corner of the drawn rectangle.

You can now insert the jigsaw into one of these holes and begin cutting out the shape.

Allow for a gap for the carpet as mentioned previously. Try and cut this as neatly and straight as possible as you will reuse this plank for the hatch door.

If you want to add another hatch for either a cooler or general storage, follow the same steps as before. Try put these hatches as far apart as possible to assist with stability.

4. Build the frame

Once the deck has been cut out you can begin building the frame.

You should keep the frame as light as possible as you don’t want to weigh the front of the boat down leading to stability problems.

Ideally a 2×1 white spruce will provide a good balance between weight and strength, but any marine rated wood will work.

Firstly, you will want to frame out the underside of the deck. The exact arrangement of this frame depends on the shape of your boat, the location of the hatches and the span distance between benches on the deck.

You will want to screw down a plank on the deck so that it is just in front of the front bench as well as on the small section on the bow of the boat.

This will stop the deck from sliding backwards and forwards.

To do this measure the distance from the front of the boat to the front edge of the seat. Carry this dimension over to the underside of the deck board and screw 2×1 planks onto the deck, making sure that the screws are flush with the deck.

Next you will want to start building out the frame. This can be done by drawing out the frame arrangement on the underside of the deck plank.

The idea here is to have cross beam at least every 10 inches for a ¼” plywood board.

You will also need to build a frame around the cutouts you made in the deck to improve strength.

Depending on the span distance between benches and size of your boat you may want to include a bulkhead to transfer some of the load onto the boat. The bulkhead can be cut out using the carboard method to create a template.

You can then screw on a 2×1 inch plank along the straight edge of the bulkhead as this will allow you to then fit it to the deck.

5. Treat the wood and install the carpet

Next you will need to treat the wood to increase its useable life. Apply a few coats of marine sealant (view on Amazon) to the wood and make sure that everything is covered.

You will also need a marine grade carpet. I do not recommend using regular carpet as it is not designed to withstand the rigors of being on a boat.

The marine carpet I have used for a raised casting deck on an aluminum boat is this DIY carpet on Amazon.

Roll the carpet out face down onto a clean surface and place the deck on top of it.

Cut out the carpet with a few inches extra to allow it to be folded over later. If possible, staple the carpet down in a few places and test if you’ve allowed enough clearance for the deck to fit snugly.

Once you have confirmed this you can remove the staples and apply glue to the deck and stick on the carpet

Once stuck you can fold over the carpet and staple it onto the deck to make sure it never lifts up. Cut away any excess carpet to neaten it up.

Next you will need to cover the hatch doors using the same method, don’t forget the hatch hinges.

6. Mounting a pedestal seat

If mounting a pedestal seat, the best option is to mount it directly onto the bench seat, this will give the most stability because only mounting it to the plywood will result in a very unstable mounting.

Handy Hint: Click here to see which seats I recommend for a raised casting deck and fishing platform.

Drill the mounting holes straight through the plywood and the bench seat as this will allow you to install bolts instead of screws so if you want to remove the casting deck you can just unfasten the bolts.

You will need to ensure that you have access to these bolts, one way is to use one of the hatches as a way to reach in under the chair to get to the bolts.

The last word…

That’s my guide on how to build a raised casting deck on an aluminum boat. Apologies for the lack of photos, as it was a year ago I did this, and didn’t think at the time I would be putting a guide together.

I should be able to update this with my own photos in 12 month’s time, as I will be doing this on a used Jon boat I bought a few weeks ago.

Handy Hint: Once you have built your casting deck, it might be a great time to also re-paint your Jon boat. Here are my Jon boat painting tips with an illustrated guide of all you need to know to get the job done.