Catalina 30 depth gauge

[acox271929]

I have a 1991 Catalina 30 MK II ? Tall rig. I know the keel is 5' 6" deep. But since the transducer is mounted aft of the keel, how far is it from bottom of boat to bottom of keel ??? My depth alarm sounds at 9.0 '
Hurry because the lake level is being dropped 6" per day.
acox271929@aol.com

 

[hvbaker]

Sounder should be forward of keel. It is impossible to answer question because it could have been installed anywhere. I have mine set to give depth from bottom of keel. So for me 1 ft means that there is 12 inches from bottom of keel and about 5 ft from surface.

 

[Stu Jackson]

acox,

There are a few different methods skippers use to deal with depth.

1. Waterline to depth

2. Bottom of the keel to depth

3. Run up on a soft sandbar and read the depth on your instrument, then deal with whatever it is.

I use #3. I find if my depth sounder says 4.4, I am aground. I can do the math between the charts and my sounder.

#1 & #2 require adjusting the sounder. Usually from the back, which is a PITA if, as most are, the sounders are installed in a pod or on the cabin back.

Good luck, choose your method, your boat, your choice.

Once you figure out what way you want to use, it's pretty easy.

 

[Kingjim91]

I check mine by dropping a weighted line over the side while I'm at the dock. Then measure the wet line and compare it to the depth sounder. I use the waterline as the calibration reference. I set the alarm at 7 feet (for 5' 2" draft).
In Lake Michigan we don't have soft sandbars, just rocky reefs, and the water level has been low in recent years.

 

[Anonymous 121765]

[FONT="Arial Narrow][SIZE="3"]Acox,

Stu, HV & King posted good info.
I have an in-hull epoxyed transducer just STBD the fuel tank.
The orig. Xducer was located here.

I touch bottom @ 4.3' (or as Stu put it, 4'-4"). My measured total draft
with all extra weight such as water, fuel, beer, equip. etc. is @ 5'-6".
I once measured this on a haulout from scum line to bottom of keel.
Subtract the two & my xducer is approx. 15" below the waterline.

Another creative way is to take a straight board (or eq.) across the
cabin top hatch opening.(level) with an overhang to get a measure
to the waterline. Position it over the open companionway as far rear as
you can to get measure hopefully down to your xducer.

Measure waterline to board, then measure from board to xducer in the hull.
This should get you close to find vertically how far under the waterline your xducer is.
Measure the distance offset & you should be close. Depending on your xducer
location you may have to get creative to get this measurement. Take your time &
be as exact as you can.

Hv & I use an actual depth offset. If you have that feature, you can use
this offset for an exact depth +/-. The good news, is that being in a
liquid medium, everything is +/-.

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