Choosing a Depth Finder and Transducer

[krebsie]

We are going to install a depth finder in our 22D, and are looking for recommendations as to which one works best for a CD. My dad called Robinhood Yachts and the fella there recommended the Raymarine SD 40. He also said that in order to get the best results, use a through hull long stem transducer with a fairing block. Does anybody have any ideas on this, and if so what would you recommend?. My main concern is finding a depth package that offers a fairing block and long stem transducer. Any direction would be great.
Cheers
-Eric

[seadawg]

Hello Eric. I also have a 22D, a Raymarine auto-pilot and a Raymarine ST60+ depth sounder that I recently installed and I can vouch for their products. However I used the "in hull" transducer model P-79 supplied by Raymarine and manufactured by Airmar. Sense you won't be able to install the transducer on the centerline a fairing becomes a real project. The inside hull P-79 can accomodate up to a 22 degree deadrise angle and these are the reasons that I Chose the P-79. There are a lot of other good ideas on this board that a search will find. Charlie

[Oswego John]

He also said that in order to get the best results, use a through hull long stem transducer with a fairing block. Does anybody have any ideas on this, and if so what would you recommend?. My main concern is finding a depth package that offers a fairing block and long stem transducer. Any direction would be great.
Cheers
-Eric

Does anybody have any ideas on this, and if so what would you recommend?

Hi Eric,

I have to go along with seadawg. Yes, Raymarine puts out a good product. However, I think that I'd go for the in-hull transducer, too, rather than punch another hole in the bottom of my hull.

There is all kinds of info in the archives about installing an in-hull unit. Tells all about mineral oil reservoir, etc. Some don't use it, some do.

The fairing helps in securing a flat based object to a curved surface, which the bottom of the hull is curved.

There is one point that I had previously touched upon and now is another opportunity to mention it again. Several years ago a person called me and asked if I would go over and take a look at his project. While his boat was on the hard, he was installing a depth sounder and was having trouble getting the transducer perfectly level. Things weren't going well for him.

I took a look at the project and at all the pains he was taking to try to get it perfectly level. He was down in the bowels of the boat getting more frustrated as time passed by.

He had it fairly level. I looked at it and said, "Good enough, nail it." He was astonished by my remark. I asked him if he had the boat perfectly leveled before he strove for perfection. I also told him to forget level, man. Just get it close. He didn't understand.

I explained that the transponder would be level maybe eighteen times in a 24 hour day. As perfectly level as it may seem to be, as soon as you step into your little cockpit, it's out of level. Then your fat brother-in-law plops down opposite you, it swings the other way. You hoist the sails in a 12 K breeze and the boat heels over. About then the boat begins to hobby horse in the chop.

Level, forget it. Get it as close as practical, but don't sweat for perfection. Now, what some people do and this is up to you. Do you want to know what the depth is a little ahead of where you are now, or do you want to know what the depth is directly under you?

Some people pitch the transducer at a slight angle forward and others have it pointing as straight down as possible.

In conclusion, there's one last thing to mention. I have no conclusive proof of it, just what I read and hearsay of others. I think that using a through the hull transducer might offer better performance than an in-hull transducer. But if an in-hull one gives you ample clarity and performance through the ranges, I feel that any difference is well worth the trade off of punching another hole in the hull.

Good luck,
O J

[krebsie]

Thanks for the info......I will be positing a picture slide show in a couple months of the restoration of Manchester, so stay tuned!
Thanks again
-Eric