Transducer Tricks - Sail Magazine

Transducer Tricks

Brian Naznitsky of Kings Park, New York, asks:"I recently purchased a depthsounder and want to mount its transducer inside the hull of my boat. The manufacturer recommends I flood my bilge and move the transducer to different positions, temporarily holding it in place with a bag filled with sand, until I find the best spot to permanently mount it. Filling the very slack
Author:
Publish date:

Brian Naznitsky of Kings Park, New York, asks:

"I recently purchased a depthsounder and want to mount its transducer inside the hull of my boat. The manufacturer recommends I flood my bilge and move the transducer to different positions, temporarily holding it in place with a bag filled with sand, until I find the best spot to permanently mount it. Filling the very slack bilge of my boat with water is not something I want to do. The water will certainly lap over the cabin sole when the boat is slightly heeled. Is there a putty or temporary adhesive I could use instead? Also, how do you recommend the transducer be permanently mounted inside the hull?"

Gordon West replies:

Filling the bilge with water won’t be necessary. Here is a much easier way to find the “sweet spot” for an inside-the-hull transducer mount. First, you want a spot clear of the keel, preferably forward of it. It should also be a spot where the hull is solid fiberglass with no core or voids.

To test locations, go for a sail. Get into about 20 fathoms of water and temporarily dangle the transducer over the side to see if you’ve got a strong bottom reading. Once you get a strong reading, head for the bilge and put your transducer in a plastic baggy filled with sea water. Hold the transducer in its baggy so it points straight down and squish the bag against the hull. Move it around and have someone on deck report when it is reading best. Again, make sure the transducer is pointing straight down, not at the hull’s deadrise angle.

Once you find a sweet spot that yields good sounder readings, mark it and head back to the dock. Now build a simple chest for the transducer (a short length of PVC pipe cut at an angle often works well), bond it to the hull, and fill it with mineral oil. Install the transducer in the chest pointing straight down and go for another sea trial.

With this sort of in-hull installation, your depthsounder’s accuracy will not be affected, only its maximum range, which may be decreased by 25 to 45 percent.

Related

01b_WALKING-KEDGE-OUT-cmykpromo

Getting More Use From Kedge Anchors

If you are cruising, you need at least two anchors on board for the simple reason that you must have a backup. Imagine having to slip your anchor on a stormy night with other boats dragging down on yours, or having your rope rode severed by some unseen underwater obstacle, ...read more

SailAwayCharter

How-to: Navigating on a Bareboat Charter

So you graduated from navigation class where you practiced dead reckoning, doubling the angle on the bow and maybe even celestial nav, and you now feel well prepared for your first charter trip. Well, you won’t be doing any of that on vacation—not past the first day, anyway.Most ...read more

04-Turtle-rescue

Turtle Rescue in the Vic-Maui

Strange and often wonderful things can happen in the course of an offshore sailboat race, and one of the strangest and most wonderful things we’ve heard of recently took place during the 2,300-mile 2018 Vic-Maui race, from Victoria, British Columbia, to Lahaina, Hawaii.It ...read more

dorcap-open-blue

ATN Inc: Dorcap

COOL SLEEPYou’re fast asleep in a snug anchorage, forehatch open to catch the breeze, when you’re rudely awakened by a sneaky rain squall. Now you’re not only awake and wet, you’re sweltering with the hatch closed. Sucks, right? That’s why ATN came up with the Dorcap, an ...read more

HIGH-RES-29312-Tahiti-GSP

Ask Sail: Who has the right-of-way

WHO HAS RIGHT-OF-WAY?Q: I sail in Narragansett Bay, which is a relatively narrow body of water that has upwind boats generally going south and downwind boats generally going north. When sailboats are racing, the starboard tack boat has the right-of-way over the port tack boat, so ...read more

albinheaters

Albin Pump Marine: Marine Water Heaters

IN HOT WATERSweden’s Albin Pump Marine has introduced its line of marine water heaters to the United States. Complete with 130V or 230V AC electric elements, the heaters can be plumbed into the engine cooling system. They feature ceramic-lined cylindrical tanks in 5, 8, 12 and ...read more

03-squalls4

Squall Strategies

Our first encounter with a big squall was sailing from San Diego to Ensenada, Mexico. We left at 0200 to ensure we’d get into Ensenada before our 1300 haulout time. The National Weather Service had forecast consistent 15-20 knot winds from the northwest, which was perfect for the ...read more