Do It Yourself RADAR Arches

Do It Yourself RADAR Arches

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Building your own set of radar arches for your boat requires a lot of planning and commitment beforehand. Radar arches are a fitted set of pieces, usually made of stainless steel or high-quality aluminum or fiberglass, that attach to a cruising boat to provide a convenient place for radar equipment. The arches are also handy for antennas, flag poles, solar panels, dingy attachments and swimming platforms, and can be fitted with nylon or mesh fabric across the top to create a sun shade.

Items you will need

  • Measuring tape

  • Drawing paper and pencil

  • PVC pipe

  • PVC fasteners

  • Stainless steel pieces

  • Handheld AC stick welder

  • Welding gloves

  • Welding face-shield or goggles

  • Round file or emery paper

  • Metal polish (optional)

  • Steel or metal flats

  • Heavy-duty drill

  • Large durable screws

Step 1

Step 1

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Make exact measurements of your vessel, where you want the arches to be fitted, and how long and how high they should be. As there are a wide variety of styles of radar arches you can design, check out some photos first to see what other boat owners have done. Sketch out a detailed drawing of your boat, including all the measurements from the port, stern, sides and the top. Your arches can't be too big that they hinder operation of the vessel, or obstruct paths for moving around or climbing on and off-board.

Step 2

Step 2

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Practice building a prototype. Since radar arches are usually made of very solid, durable metal or other material, it's good practice to design your arches first in something you can easily adjust, reshape or recut. PVC pipe is a very good substitute, as it is somewhat sturdy, and comes in many shapes and sizes. Fit together with fasteners to form the kind of arrangement you'd like best. You'll want to fit the arches in a way that anchors to the stern pulpit, which is the railing around the stern.

Step 3

Step 3 Images

Examine the PVC model of your arches from every angle, and make notes of the measurements, the thickness and the amount of pieces involved as exact as possible. Duplicate your model using steel, aluminum or heavy fiberglass. Using a handheld AC stick welder, weld each piece together. Start with one piece at a time, three welds in a row per connection, and then as you finish each connection, sand with a round file and some emery paper. When your design is finished, use metal polish if you used stainless steel or aluminum.

Step 4

Attaching the arches to the boat itself requires solid steel plates to fasten to the ends of your finished arches. Use a heavy-duty drill to make some holes in several flat pieces of steel about a quarter-inch thick, and then weld these pieces on the ends of your arches. Again take measurements for your boat's stern and top, and drill corresponding holes into the top of the surface. Fiberglass will be easier to drill through. Attach the arches using large, durable screws through the plating and into the stern, and you're ready to sail.


  • Be extremely careful using a welder. Metal gloves, faceplate, and heat-resistant and flame retardant clothing are a must.
  • If your boat is often anchored at a marina, check that your arches adhere to the rules and regulations. Individuality isn't always welcome nor appreciated.


  • Stainless steel is best for any type of structure that will see a lot of wear, but if you use fiberglass, you can paint your arches.
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