Soaked fishfinder

Has anyone had any experience with soaked fishfinders? I mean flipped the yak and the finder got submerged...
Would the unit still operatable after a dunk? Or numerous dunks.

I plan on putting a finder on the yak, but not so sure now since my first dunk this past Sunday near the Berkeley pier. It took me at least five tries to get back on. I would imagine the finder would be completely soaked and damaged beyond repair at this point.

I mean I don't wanna put it on there, if it's just gonna get damaged rather quickly.
Some of you guys are probaly thinking..."well don't flip then man"....but hey stuff happens...

Most fishfinders should withstand being submerged.  My old Humminbird Pirhana really took a beating before it died (and they are among the more susceptible units to leaking).  It got tossed and tumbled at on beach landings on many occasions.  I'm confident that my Fisheasy 240 would have no problem with being submerged... it takes a lot of waves as it is. 

Key is to put dielectric grease on all electrical / signal connections and seal up any unused plug-receptacles with silicone to minimize the chance of water intrusion or corrosion issues.

If possible, the best would be to rig it so you can take the FF off and stow it below decks for rough surf landings.

Erik

I am going to be removing the fishfinder like you recommend on any and all landings just in case for my new ff and yak. The one reason I didn't do that before is I was worried if the raw battery wire could discharge and possibly shock me or blow up the battery if it were submerged. Is there any evidence to believe that is safe or unsafe?

I know 12 volts doesn't have a whole lot of voltage for shocking a person under water (amps are more important in terms of harmful shocks but volts are important for penetration when we talk about such low voltages) but is 8 amp/hrs a lot of current? Isn't that pretty much a power tool?

Erik,

You should try and get a sponsership from your dielectric grease maker... this has got to be the fifth post about the stuff from you in the last week. 

Brian

An occasional quick dunk should be OK since they claim the units to be 'waterproof'.
I have a big horse trough I fill with fresh water after all my salt water outings and all my gear goes in the trough. My son put both of our FF's in the trough without my knowing. They got a GOOD soaking before I found out about it. They we both pretty well filled with water. Bad news. The good news was that it was fresh water. I had to disassemble each unit and leave them apart to dry. Funny thing about the Humminbird 535, they actually use a thin piece of foam ( SPONGE ) between the circuit board and the unit. All this does it absorb water and hold it against the circuit board. The thing was loaded with water.
After a GOOD drying both units worked fine.

Erik,
You should try and get a sponsership from your dielectric grease maker... this has got to be the fifth post about the stuff from you in the last week. 
Brian

It's the new duct tape... it's also probably a panacea for what ails ya.  "Got pain... put a little dielectric grease on it and get back out there."

Gato... as for your safety questions. The combination of low voltage (12 V) and the fact that it is Direct Current rather than AC makes these systems very safe.  The battery won't blow up or shock you if you dump. It's that simple. 

Gato... as for your safety questions. The combination of low voltage (12 V) and the fact that it is Direct Current rather than AC makes these systems very safe.  The battery won't blow up or shock you if you dump. It's that simple. 

Well, a 12V DC source could kill you IF, and this is a big IF, it were able to supply the current across your body resistance.  It takes 300-500 mA of current to induce ventricular fibrillation.  There is no way a battery of the types we use can sustain this current across a human body resistance.

BTW, 8 Ah is not a rating of the max instantaneous current a battery can source.   It is a rating of how much sustained current a battery could source for 1 hour.

-Allen

Alright you've allayed my fears. Thanks. 

Well, a 12V DC source could kill you IF, and this is a big IF, it were able to supply the current across your body resistance. It takes 300-500 mA of current to induce ventricular fibrillation. There is no way a battery of the types we use can sustain this current across a human body resistance.

Exactly... it's all about Ohm's law.  My understanding is that a true electrocution hazard is very unlikely (except possibly under some very unusual circumstances) with anything less than about 30 V DC... that's why it's used for "control voltage".  It's not to say you won't feel it or it won't be uncomfortable if you are shocked, but the body's resistance is generally too great to present any significant hazard. 

There are all kinds of other nuances regarding electrical safety of DC versus AC as well... with AC causing fibrillation due to the 60 hz frequency... where DC causes muscles to seize (tetanus) rather than truely fibrillate.  Blah Blah Blah...

Oh ... and the 300-500 mA is DC current.  It takes less AC current.  blah blah blah ...

-Allen

I once forgot my 12v battery in my truck and ran back to grab it... I had on my nice wet wetsuit and my keys were still in my hand as I grabbed the battery.  Anyway, the keys connected to the terminals... I got a nice shock, a small cauterized cut on my finger, a burnt terminal and a what looked to be weld mark on one of my keys.

I rolled with my brand new Humminbird and it works fine.  I agree with the dielectric grease recommendation although I did not have any in place at the time.  When i purchased my FF from West Marine they offered a replacement warranty extension that would replace the unit for any reason for up to 3 years.  While I do not usually believe in extended warranties, I bought this one knowing that the FF would be submerged periodically and possibly also impacted on a rough beach landing.  For $35 it seemed well worth it.  With regard to the battery discharge, Ii would be more concerned about the corrosion to the contacts and conductors than the potential of electrical shock.  Don't forget that the current and voltage would dissipate quickly in a large body of salt water.

I am currently rigging my Fish-n-Dive and have been thinking allot about this very subject.  Like many here I also dive and I have an underwater housing for my video camera.  Wouldn't it be possible to build a housing for a fishfinder.  It really wouldn't need to be depth rated like a camera housing. but lexan and silicon should do the trick.  I may even order some of those fancy camera housing buttons so that all the finder features are accessible from outside.  If I work something out I'll keep everybody  informed.

Thanks for the input fellas. Since I lost around $900 worth of stuff this past Sunday, damaging a used $50 fishfinder doesn't sound too bad.


Thanks again...