Stealth sounder setup: Installation of a fully removable sounder without cutting holes in your kayak

Most sounder installations in Stealth Kayaks involve cutting holes in the fish box and installing the transducer on the outer skin of the kayak, with the transducer either glued in place or installed in a wet mount.  The glued method makes it impossible to remove the transducer and wiring after a fishing trip while the wet mount makes it difficult and time consuming to do so. As a kayak hatch never really dries out, leaving the wiring inside increases the risk of corrosion.  My first transducer was glued in place and the wiring suffered some corrosion issues so I decided to find a way of installing a sounder that meets the following requirements:

1. Is quick and easy to install or remove the sounder plus all wiring.

2. Requires no holes to be cut or drilled in the kayak (suits those with new yaks who are reluctant to cut holes in their prized toy)

Scott McIntosh (Lazybugger) has successfully mounted his transducer under the kayak seat so I thought I would try this method (thanks Scott for the idea).  I placed the transducer in a plastic bag containing water, put the kayak in a river, connected the battery, then moved the transducer around under the seat until I found a point where the signal passed straight though the hull (i.e. the glue between the outer shell and fish box contained no air bubbles).  Having found the spot I marked it.

Using a block of high density foam (cost $5) I cut out the shape of the transducer (must be a tight fit) and glued it in place at the marked spot under the seat.  The position under the seat is ideal as it is too small to store anything else and is out of reach when you are in the kayak, so is effectively wasted space.  I used T- Rex Power Bond, but whatever glue you use the seal between the kayak and foam must be watertight as you will need to put some water in the hole before inserting the transducer.  

Hole cut in the foam to house the transducer (view from underneath)

Transducer inserted in the hole in the foam

Foam glued in place under the seat

To power the sounder I use a 12 volt 1 Amp. Hr. battery that is only 10 cm long and 4 cm wide and is sufficient to last my full fishing trip (tested up to 8 hours). I have a battery box already installed but if you do not want to cut holes in your kayak this battery could be easily installed in a small plastic box under the seat, or possibly even in another block of foam glued in place with a hole the shape of the battery (again make it a tight fit).

Small battery - with a 50 cent coin for scale

I house the sounder in a plastic box and attach this to the lid of the fish box with good strength 3M Dual Lock (similar to Velcro).  I have never had a problem with the box being knocked off when out at sea, but obviously when coming in through the surf I remove the box and place it in the hatch.  The reason I use a box is to keep the sounder away from water as far as possible and out of the glare of the sun (but it does still get water droplets on it).  One negative is that the box does take up space in the hatch so if I had to re-do this I would make it as small as possible.  Once the box is in the hatch I rest the rod buts on it which helps keep the reels away from any water or fish blood.  

Inside the hatch I have glued in two straps retrieved from a discarded back pack which I use to strap the sounder box in place while crossing the surf zone.

Sounder in the box

Sounder box mounted on the hatch lid with Velcro

Straps on the bottom of the fish hatch to attach the sounder box

Sounder box strapped in for crossing the surf zone

Strips of Velcro or some type of clips attached along the inside wall of the fish hatch are useful to keep the wiring off the floor and out of the way.  It takes me less than 5 minutes to put the sounder with wiring and transducer in (which I do the night before fishing when loading up), and less than 2 minutes to take it out after the trip. Just remember to add some water to the transducer hole before setting out or the sounder will not work.

That's it.  A method worth considering if you want to easily remove your sounder after each trip or if you don't want to take the knife to your nice new Stealth yak!

Tight lines,
Dave (tunny)