Depth/Height - Forward Looking Sonar -58' Yachtfish

[ralexa6808]

A number of questions all kinda related. Didn't want to make separate posts for each. Thought it made sense to combine them in one post. Any advise you can offer would be appreciated.

I did a search of the Forum looking for info about Forward Looking Sonar and it's usefulness (or lack thereof). Saw some posts from 5 plus years ago. Was wondering if there has been any advancements anyone can enlighten me about regarding improvement of only being able to look forward about 8 times current depth. The consensus about where to mount the transducer (engine room bilge area)puts it back 20+ feet from the bow, leaving little time to react.

The reason I'm asking is:
I have seen depths ranging from 4 feet (a Hatteras spec sheet someone here copied and posted, 4 feet 9 inches, 4 feet 10 inches (from various sources - Owners on Yachtworld), and when I bought the boat from the PO I was told I needed 5 feet of water under the boat.

Also on the other end of the scale I have also seen 17 to 19 feet AWL height to the top of the fly bridge windshield.

Why is there so much variability, even some Hatteras Brochure / Information Specs differ.....did something change over the years of production?

Other than waiting until I do a bottom job in the next year or two it bugs the hell out of me not knowing exactly how deep She sits. I understand Fuel, Water, Furniture, and Fat Relatives not withstanding. Just looking for a straight answer, if that's possible in this fuzzy math / almost accurate / kinda got it right world we now live in....sorry if I'm ranting, I remember a time when accuracy was important.

 

[Boatsb]

Run the boat aground and set the depth offset to 0. Then no matter who says what when you hit zero you stop.

I don't run in less than 5 foot unless I'm off course. I draw 3 and change so that leaves me a pad. If I know I need 3 foot 10 and tried to run in 4 foot I'd probably find a high spot a d do some damage

 

[PeterK]

Some of the best "gadget" info I have seen is by Ben Ellison at panbp.com He is now a staff writer at PMY mag.

 

[crosswind]

hello I also have a 58 yachtfish and consider 5 ft a min and even try to avoid that

now about forward looking you make no mention as to brand as this year I bought a new garmin 6012
that could also get forward looking transducer which was so new I had to wait for stock till they
could ship it
After receiving it I read where it was to mount on a trolling motor or the transom so after many talks
with Garmin I sent it back to await the in development transducer coming out ( WHEN ? )

 

[Cricket]

The forward scan sonar isn't going to help distinguish water depth to within inches or a 1 foot, it's to see what's out front more as big picture as in a ledge/rocks/structure/fish/etc.

 

[Pascal]

If measuring on the hard you need to make sure the boat and th ground is perfectly level, not always th case.

What I ve done before is dive under the boat when anchored in shallow water and actually measured the distance between the tip of th wheels and the bottom. Again you need to make sure you do it when you re not swinging much or when swiping over a flat bottom. You can then set the offset on th sounder to show the exact actual water depth (my preference) or the deoth unde the prop as some prefer

what depth is comfortable depends on where you are are how well you know the bottom. In fairly unfamiliar waters I will usually rarely venture in areas where I won't have two feet under the wheels. This also requires accurate tide info which is pretty easy to get nowadays.

There are a number of anchorages in the Exumas that we frequently visit that we can only get in at mid to high tide. I ve squeaked in with barely a foot under the wheels but only because I know the bottom and I have saved accurate GPS tracks. In some spots, I have actually snorkeled to check for any obstructions

 

[Boatsb]

On the hard you need a level. A laser and a tape. It's not that hard to find the lie of the boat, shoot a level and measure depth. Then add 2 feet to be safe.