Forward looking sonar

[FWT]

Thanks Dave.

I also toyed with the idea of the direction of personal bathy charts. That with crowd sourcing sharing seems to be the cutting edge. I couldn’t make that make sense for me. Would be useful to stay up to date on shoaling in frequent haunts. But it doesn’t seem to be ready for prime time.

 

[DSC]

We have a Wesmar 360 deg sonar installed by the previous owner. A prove lowers down below the hull when in use and is capable of a continuous scan or a defined sector scan (like radar). The angle of scan can be adjusted from horizontal to almost vertical. Range is adjustable from 100 ft to hundreds of feet. This is an older unit but Wesmar is still available although typically used on commercial installations on larger boats where I have also used them. When retracted, the probe hoists up into the moon pool. When down, the probe is about 18" or so below the hull. Runs fine at hull speed but would not use when planing. Display is excellent with very good resolution. Has been of great assistance in narrow channels, checking for rocks and reefs in anchorages not on the chart and has alerted me to at least one sand bar sticking out from the side of an island where it was not expected. Principal downside is that it is one more thing to keep track of but it is useful. Wesmar continues to make commercial sonars but I have not used the newest models. Moon pool with 6" hole (rough measurement) through the bottom is required and it is one more thing in the engine room.

 

[boomerang]

We installed a Wesmar and a Simrad on 2 boats 5-6 years ago. You're right, the Wesmar is a 360 degree searchlight sonar. The Simrad is also a 360 but it's omnidirectional and takes a 360 degree "snapshot" all around each time it pings. The picture is superior because it's real time vs history. The Wesmar is being removed and replaced with a Simrad. The wesmar is a great little searchlight sonar but tiny in comparison to the SX93. The Simrad high hat (what you call a moon pole?) is about as big around as a bushel basket and when the transducer is retracted, the thing stands about 10' off of the floor! It just wouldn't make sense to have any type of a sonar with a lowerable xducer to be used in shallow water.
PS if anyone is interested in a Wesmar system that's literally been used probably less than a dozen times, let me know. I'm sure it can be bought for a fraction of the cost of a new one.
Attached is a picture of a Simrad transducer lowered while on drydock to give folks an idea of the size and how much is exposed while fully deployed.