Monday, April 2, 2012

Part 1: I gotta have more power...... I rewired it!!  Sorry - had to channel my inner Tim Allen and Christopher Walken's SNL skit there for a moment.  But I digress........

Several of my friends have been anxiously awaiting my next modification to the Hobie Revolution 13.  When people heard that I was taking a different approach to powering my fish finder, they were intrigued to say the least.  Before I get into the details of the modification I performed this past weekend, there are a few key factors that must be understood for why I opted for the method I did.

First, I do not have the Hobie First Aid kit gear bucket accessory that many stow in the rear hatch.  Second, I do not use the rear hatch for any storage other than potentially a small dry bag while on the water.  Third, I was determined to use as many Hobie products as possible yet still educate others on how this install could still apply using the same concepts with other materials and kayaks if they so choose.  Fourth, I was determined to keep the installation as waterproof as possible, having had to replace too many corroded connectors in my last kayak due to saltwater corrosion.  Fifth, the battery box would need to be secured and not move around while either on the water or during transport yet still afford removal of the battery for charging when necessary or during transport.  Try lifting a kayak solo with the extra weight of a 12v battery and you'll quickly understand my reasoning.

Understanding these factors will help you understand the method to my madness, and with that said, the first part of my fish finder installation began..........

Phase 1: Power

The parts I used were:

1 - Hobie Full Size Fish Finder kit (not all the pieces will be used in this part of the install)
1 - Hobie Deep Gear Bucket
1 - small piece of STS or other gasket-like material (2-3" piece will suffice)
1 - Liquid Tight wire fitting (wire size .08-.24)
1 - Dremel tool with a cutting bit
For those new to the Hobie accessory line, the Hobie Full Size Fish Finder kit (Part # 72020039) includes a sealed 12v battery with an integrated waterproof power connector already silicone sealed to the battery.  The accompanying charger has a receptacle that plugs right into the battery making charging very easy.  For this installation, I only used the foam battery block, the wiring harness and the battery.  The rest of the pieces will be utilized when I install the fish finder.  One important note about the foam battery block - the block is designed to be snug fit for the battery to sit in.  For my installation to work; however, the foam block will be have the outer edges trimmed and inner opening enlarged and not adhered to the hull of the kayak.

First, I removed the lid from the Hobie Deep Gear Bucket (Part# 74704021) and placed the foam block gently on the top of the gear bucket so as to not disfigure the bucket sides and cause an inaccurate sight line for the trimming I was about to perform.  I used a regular ball point pen and started with the closest corner to mark where I needed to trim.  My plan was to install the foam block in such a manner to not only allow the battery to sit upright to further reduce the chances of water corrosion from any potential standing water in the bucket, but also to make connecting and disconnecting the battery easier for when it was time to recharge it. The key here is to use some form of power cutting tool or rough sand paper to remove the excess foam but only a little at a time.  Once the foam is removed there is no re-adhering it back.
Your goal is to have the foam block slide into the gear bucket but not push the sides out.  In order to do this properly, you have to taper the lower portion of the outside walls of the foam block as well, since the gear bucket tapers.  If you don't, the foam block will not fit, prevents a watertight seal of the lid ultimately causing the bucket to widen and disfigure and preventing proper closure and sealing of the Hobie hatch.  The last part of modifying the foam block is to enlarge the inner cutout slightly.

If you insert the battery into the foam block prior to enlarging the cutout, you will again cause the bucket to deform and not fit inside the hatch opening cleanly.  I only removed approximately an 1/8" of the inner cutout along the lower and side edges.  Once the additional trimming is done, the battery should slide freely in and out of the foam block, and the block itself will most likely move freely inside the gear bucket.
The next step is to make a small hole in the scalloped cutout on the gear bucket.  Using the same Dremel cutting bit, you can push it right through the plastic wall of the gear bucket and begin to enlarge the hole with small circular motions.  Remember, your goal here is to make the hole large enough to accept the liquid tight fitting but not large enough for it to slide freely in and out.  When the cutout is just barely large enough to fit the end of the fitting but not pass through, stop your cutting and thread the liquid tight fitting into the gear bucket from the outside in.  The threads on the fitting increase the waterproof functionality I was adamant about retaining.  Once it is installed, I cutout a small hole in my piece of STS to act as a washer/waterproof barrier to fit around the fitting on the inside of the gear bucket, yet still remain snug.  The reason I opted for the STS is that is has a tacky backing and adheres  to almost any surface.  Once I had the sizing correct, I removed the backing on the STS and placed it over the fitting and adhered it to the inner wall of the gear bucket.  I then installed the inner locking nut of the fitting and tightened it down to create a secondary water tight barrier.
With the inner portion completed, I then installed the outer water tight top nut to test it.  When I install the wiring for the fish finder, I will add a small dollop of Lexel inside the fitting for the final waterproof step but for now, the opening was left unsealed for demonstration purposes.
I then re-inserted the battery, slid the foam block in place, inserted the wiring harness through the fitting to test out all of the pieces.....(NOTE: do not connect the harness to the battery - it is LIVE and can be an electrical shock hazard.  The image below does not have the harness fully connected).
The wire harness shown above is the two wire connector provided in the Hobie Full Size Fish Finder kit that marries to the battery harness clip as shown above.  This is the power wire that I will be connecting to the fish finder power cable provided with any fish finder package you purchase.  The final product of all this work took a mere 30 minutes total time and now provides me with the ability to have power on the water for my fish finder, remain virtually waterproof and have the battery be fully removable to recharge yet secure while on the water or during transport.  One final note on the power - an inline fuse will be installed inside the gear bucket when I make the final connections, but it was not installed at this time.

While some may not prefer the permanent fixture of the gear bucket, the weight is minimal at best, since the battery will be removed and installed when needed and not transported in the hatch.  Doing so might result in loosening the gear bucket lid and allowing water in which is the next to last piece of the waterproofing puzzle, the last piece being the hatch itself on the Hobie.
I hope you find this installation helpful and possibly inspire you to think outside the box the next time you are looking to add power to your respective kayak.  The next phase of this project is the installation of the fish finder.

Until next time - tight lines, be safe, take a kid fishing and thank any service member you come in contact with for the protection of your freedoms they provide.


  1. Looks great Chuck, thanks for documenting and sharing! (Watch out Tim Allen)

  2. The idea you have implemented is really awesome. You will require good cables which can be submerged under the water. Best of luck.

    rg-59 cable suppliers

    1. Thanks - do you have any input on which ones? I am constantly trying to make the setup more bulletproof.