Echomap Plus 73CV: Do I understand this correctly?... the only way to mark a 'Waypoint' is to hit the mark button? This only marks the screen location with GPS, NOT where the transducer is located on my boat. Correct? Which means I'm always off by 6 feet even when right over an object?

It's worse than that.

 

"Garmin® GPS receivers are accurate to within 15 meters (49 feet) 95% of the time. Generally, users will see accuracy within 5 to 10 meters (16 to 33 feet) under normal conditions."

 

https://support.garmin.com/en-US/?faq=aZc8RezeAb9LjCDpJplTY7

So unless you throw a marker buoy into the water when going over an object...you are NOT going to know exactly where that brush pile is under the water?  I'm thinking no way.

9 minutes ago, Bartableman7 said:

So unless you throw a marker buoy into the water when going over an object...you are NOT going to know exactly where that brush pile is under the water?  I'm thinking no way.

Welcome to the wonderful world of marine electronics - people rely on the GPS much-too-much when the accuracy isn't there to justify it.

 

Now if you had several thousand dollars to toss into a GNSS system (type surveyors use for GPS locating), then you could trust it...those are accurate to inches...but systems start at around $10k...and that's just for the GPS and maps.

No experience with Garmin. Accuracy that averages 15 meters is unacceptable. I would be replacing them.

You don't need a $10000.00 unit to get accuracy.

My hummingbird helix units are usually within 3 meters.

If I mark a brushpile I can go right to it with my units. 

I can sit on a brushpile using GPS and sonar will show it directly under me.

Most reservoirs I fish have lots of brushpiles.

I can't remember the last time I used a marker buoy.

 

I think they've gotten a lot better MN.  GPS accuracy has improved greatly. Supposedly the GPS signal from the Satellites used to get scrambled for security reasons. Probably so they ( commie invader bass fisherman ) wouldn't use missiles on bass fisherman that are on their spots. 

FM   

53 minutes ago, Fishingmickey said:

Supposedly the GPS signal from the Satellites used to get scrambled for security reasons.

You'd think Garmin would have updated their information in the past 21 years...

1 hour ago, Smalls said:

You'd think Garmin would have updated their information in the past 21 years...

Or updated the web page.

 

My Echomap CV plus on my kayak puts me with in a few feet of any waypoint I mark.  I don't have to mark a waypoint as I pass over it.  I can scroll back my sonar screen and mark the object on the fish finder screen.  That waypoint will be right on the money.  I still use marker buoys most of the time to mark the spot to cast to, but locating the waypoint on gps map is accurate.