Catalina 350 International Association

We are new owners of hull 493 and need some information. I want to set the offset for the depth finder to the bottom of the keel, but I can't find the actual depth of the keel from the bottom of the hull where the transducer is to the bottom of the keel. Does anyone know what the offset should be? Thanks.

blake,
welcome! what an awesome boat. I have hull #318 "Chanticleer" here on the Tennessee River. I too have the wing and offset my depth to bottom of the keel. It's been a couple of years, but I believe the depth of the transducer is approx. 3'. A good way to check this is, while at the dock, take a tape measure or lead-line (assuming you're not in deep water at dock), and take a depth of water measure amid-ship on both sides of boat to see if the bottom is pretty flat at that spot. If not, you may have to average. This should give you actual depth, then when you set the offset, just make sure this agrees with the depth, minus 4.5 feet. I have kept that setting now for a couple of years, but I must say that I think I'm going to change it back to actual depth, and just do the math on the keel in my head. There's mixed opinions about it, and whatever works best for you is the way to do it. Talk to you soon. -Alex

blake,

we own hull #451, and our dealer set up our offset at +1.6, or 1.5. I believe which would agree with alex's 3 foot depth of the transducer. I will check for sure on the + or -. Raymarine!
I am not at the boat now, but am going today and will check it out.
Anyway, I know it is accurate because we have run aground and it was spot on.

Congrats on the new 350, I am sure you will enjoy. We are off to go sailing for the day

Richard

When I hauled out for my survey I had the surveyor measure the draft from the normal water line to the bottom of the keel. It was closer to 5.0 ft than the 4.5 feet specified in the specifications (wing keel). I use 2 feet as an offset.
Lyle Hanna
Serenity
Hull #363

We set ours this past weekend at +2 which we felt gave us a .6" buffer in the event the 4'6" keel was more like 5' when the boat is fully loaded. The First Mate will be less stressed at this setting, too

Wow. I thought this issue was a no-brainer! I wish we could poll the members as to which offset they use. I had to replace my depth unit and can't decide which way to go. However I am pretty sure that if you use a + depth, you are moving the reading to close to the waterline (true water depth). A minus sign would give you the depth below the wing. Since the boat MUST be able to navigate in water that is at least deep enough to miss the keel, wouldn't be best to use the minus figure, i.e., say -5 feet? If you wanted to know the actual depth, then simply add 5 to the reading.

am I missing something?

thanks

dave

On the Cruisers Forum it is 50/50 on offset! But, just to make sure, if there is no offset and the transducer is 3 feet below the waterline (+/-), then a reading of say 4.5 feet means that there is still 3 feet BELOW the 4.5 feet draft keel depth (i.e., a F.S.)

Can someone show me why I am wrong....yet again?

thanks, Dave
Nybor #411

Dave,

No "here is the correct way to set offset/no offset". As long as anyone at the helm KNOWS how it is set!

My preference is to set offset so it reads from water level. This allows one to instantly compare depth readings to chart readings. Much easier when you are tired than having to do the math in your head.

Your math is correct.