Best way to mount downriggers on narrow gunnels?

[magic conch shell]

I just picked up a 2004 Crestliner 1850 Sportfish with a 115 Yamaha and kicker, and I'm looking to add downriggers. Problem is, the gunnels are too narrow for standard swivel bases. I've looked at track systems, but there's about 3/4" of sprayed flotation under the gunnels, and the tracks aren't cheap. Does anyone here have a good workaround for mounting without tearing out a bunch of foam?

 

[alesana4ever]

My buddy had the same issue on his Crestliner. He ended up using backing plates under the gunnel with a smaller track system. Didnt have to rip out much foam, just trimmed a bit to fit the hardware. Been solid for a couple seasons now.

 

[strongboat_]

My buddy had the same issue on his Crestliner. He ended up using backing plates under the gunnel with a smaller track system. Didnt have to rip out much foam, just trimmed a bit to fit the hardware. Been solid for a couple seasons now.

yes! this is exactly what I was thinking. You can still mount a swivel base directly on the gunnel without tearing out all the foam. Let me add one tip, that The key is to use a big, solid aluminum or stainless steel backing plate on the underside. You can use a hole saw to just clear the foam for the bolt holes and then seal them up tight.
This spreads the load and gives you a rock solid mount without compromising the flotation. Just make sure the backing plate is big enough to distribute the force