Depth Finder Basics

[l008com]

I need a simple depth finder and I have a few basic questions. The one I'm leaning towards is the Humminbird 610. First question, puck or transom mount? I don't like the idea of something hanging off the back of my boat dragging in the water. Plus I'm not a fan of drilling holes so low in my hull. I'm not a boat building pro yet, I'd rather play it safe. So the puck seems like the way to go, but I have two issues with that. First is that I think theres space between my floor and the bottom fiberglass of the boat. That means I can't mount it there right? It would have to be mounted in the bilge? It that ok, is it water proof enough? Also do these transducers have to me mounted flat? If they are on a sideways piece of fiberglass (my boat has a V hull), would it then be measuring the depth at an angle instead of straight down, which would give you an artificially larger number than the actual depth?

 

[foodfisher]

Re: Depth Finder Basics

Search the humminbird site. They have the mounting basics posted. If the boat in your avatar is the boat you're placing the ff on, I'd have no prob. placing it on the transom. The ff is bearly in the water with a flat surface that will ride over most debris. Don't forget, that motor is hanging off the back of your boat a lot lower than the ff will.

 

[l008com]

Re: Depth Finder Basics

Actually I read through the whole manual already which including mounting instructions for both types of transducers. I guess my biggest issue with the transom mount is that I really don't want to drill holes in my hull that are going to be underwater.

Should I not use the puck?

 

[foodfisher]

Re: Depth Finder Basics

Access to the hull? Possible inferior readings. The drainplug is thru transom and underwater. Installed properly w/correct sealant, ff won't be a concern.

 

[l008com]

Re: Depth Finder Basics

Access to the hull? Possible inferior readings. The drainplug is thru transom and underwater. Installed properly w/correct sealant, ff won't be a concern.

I don't really follow this reply. But from what I read elsewhere, general consensus is you get a more reliable reading from externally mounted transducers. How hard is it to install one of these for the first time? Again I have read the installation guide, but reading directions for doing something, and doing something, are very different things.

 

[Pez Vela]

Re: Depth Finder Basics

Your general assumptions about mounting the Humminbird shoot-thru transducer are correct. It needs to be mounted in the bilge, perpendicular to the surface of the water. An adjustable (P79) tilted element shoot-thru transducer is apparently available for some Humminbird units, to be installed in V-bottom hulls, if you can't find an accessible flat area in your bilge. A shoot-thru should work for you, and provide ample performance for simple water depth readings. The transom mount transducer has potentially better performance because it doesn't have to penetrate the fiberglass hull. It may be attached in a variety of ways without drilling or screwing it to your transom. One solution is to use an adhesive (such as 5200) to fasten a small plate to the transom, with the transducer bracket being screwed onto the plate, thus preserving the integrity of the transom. Positioning a transom mount transducer is an art unto itself in some cases, depending upon your hull configuration. Trial and error with a non-permanent attachment is not a bad idea. If you like the plate idea, you could adhere it to the transom with a relatively weak silicon seal until you get the positioning just right, and then re-attach the plate with 5200.

 

[foodfisher]

Re: Depth Finder Basics

Access to the hull? Possible inferior readings. The drainplug is thru transom and underwater. Installed properly w/correct sealant, ff won't be a concern.

Sorry for the hierogliphics(sp).1) Is the inside of the hull easily accessible for puck installation? If not, strike one. 2) Inferior readings, ie: off level mounting, air bubbles in setting blob, could be dissapointing. Strike two. 3) Your concern about holes in transom should be eased by this fact. Drainplug is a hole thru transom. Also, there are a "lot" of fishfinders on a "lot" of boats out there with no negative impacts. 4) The instructions are fairly concise, I can't help with hand/eye coordination or uncontrollable fear Really, it's no biggie. Just go slow and use 3M 4200 liberally. The ooze that goes where you don't want it will scrape off.