Association Forum - Raymarine Transducers

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Raymarine Transducers

New Topic

Topic Locked

Printer Friendly

Author

Topic

trbagpiper
1st Mate

Member Avatar

USA
33 Posts

Initially Posted - 01/21/2017 : 10:27:13

I just got a Raymarine instrument combo as part of this restoration. An i50 depth and speed with a i60 wind. I'm now wondering where would be the best place to put the thru-hull transducers. Raymarine suggests just in front of the keel which puts it in the head deck. Suggestions?

Jim Ventimiglia
Toms River Yacht Club
'78 Cat 25 #945 SK/SR "Pipe Dream"

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9013 Posts

Response Posted - 01/21/2017 : 11:17:37

You want the depth sounder to shoot reasonably vertically, so too far forward could be a problem. (The instructions probably speak to this.) I don't see a problem with it being aft of the keel, like under the quarterberth--it's not like you're going to avoid hitting something because of your depth sounder. By the time it and you detect an object, you've hit it.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 01/21/2017 11:20:43

islander
Master Marine Consultant

Members Avatar

USA
3992 Posts

Response Posted - 01/21/2017 : 11:29:42

I agree with Dave that having it forward won't stop you from hitting an object. I have a thru hull transducer and it is Mounted aft of the battery compartment in the quarter birth just to the starboard side of the companion way steps. There is a small hatch there. The hull is relatively flat in that area and it works very well. As a side benifit you don't have a long cable run if your display is mounted right above it on the bulkhead

Scott-"IMPULSE"87'C25/SR/WK/Din.#5688
Sailing out of Glen Cove,L.I Sound

Edited by - islander on 01/21/2017 11:53:20

sethp001
Mainsheet C-25 Tech Editor

Members Avatar

814 Posts

Response Posted - 01/21/2017 : 16:25:22

I recommend you install your transducer in the same place as mine was installed by the PO. My thru-hull depth sounder transducer is installed at the aft end of the compartment under the v-berth. It works well there. The hull has little incline there. Your transducer's instructions will indicate how much incline it can tolerate. Most transducers can handle some incline, which is why they still work on heeled sailboats.

The installation manual for most depth sounder transducers I have seen indicates that the transducer should be installed forward of the keel. Depth sounder manufacturers must have a good reason for making this recommendation consistently. The purpose is not to allow time to stop the boat if the depth is shallow. The purpose is to have the transducer shooting through laminar water flow in front of the keel vs potentially turbulent flow behind the keel. Eddies and cavitation are possible on the aft edge of the keel. The air bubbles from cavitation can disrupt the transducer's signal.

Seth
"Outlier" 1987 Catalina 25 SR/SK/Traditional Interior #5541
"Zoo" 1977 Morgan Out Island 30
"Nomad" 1980 Prindle 16
"Lost" 1988 Catalina Capri 14.2 (sold - yay!)
"Marine Tex 1" Unknown Origin POS 8' Fiberglass Dinghy
https://whichsailboat.com/2014/07/27/catalina-25-review/

islander
Master Marine Consultant

Members Avatar

USA
3992 Posts

Response Posted - 01/21/2017 : 17:45:35

Before you decide on a possible location I would find a suitable test dummy that is flat and the same diameter as the external head of the transducer. Hold it up to the hull and see if it rocks or has gaps on the port and starboard sides.This will give you a good idea of how the transducer will sit against the hull. If it does have gaps or rocks around I would find another location. The dummy puck could be cut from scrap plywood.

Scott-"IMPULSE"87'C25/SR/WK/Din.#5688
Sailing out of Glen Cove,L.I Sound

Dave5041
Former Mainsheet Editor

Members Avatar

USA
3754 Posts

Response Posted - 01/21/2017 : 19:51:08

Mine, too, is under the v-berth. Turbulence aft of the keel can give false readings. I know that many have installed it aft of the keel and haven't noticed a problem, but why not go for optimal? Access under the v-berth is easy and the transducer is out of the way.

Dave B. aboard Pearl
1982 TR/SK/Trad. #3399
Lake Erie/Florida Panhandle

trbagpiper
1st Mate

Members Avatar

USA
33 Posts

Response Posted - 01/22/2017 : 11:10:51

Thanks everyone for the advice on depth but one additional question, my speed transducer. Where should that go?

Jim Ventimiglia
Toms River Yacht Club
'78 Cat 25 #945 SK/SR "Pipe Dream"

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9013 Posts

Response Posted - 01/23/2017 : 14:04:22

Question: Do you have a need to know your speed through the water (ignoring currents), or is your speed over the bottom sufficient? If the latter, I suggest a GPS, which tells you how fast and where you're really going, and passing on the hole in the boat.