1. SIMRAD® BSM-3 and BSM-2 RTM 3.8 SOFTWARE UPDATE

2. Software Update Description
The RTM 3.8 software update brings many new improvements to the BSM sounder modules. This update is available free of charge from the Simrad yachting website.
Key Features for RTM 3.8:
Transducer depth offset is now a networked setting
Increased sensitivity in Low CHIRP
Increased sensitivity in High CHIRP
BSM is now retained as the sonar source after power cycling the attached MFD
Key bug fixes for RTM 3.8:
XID temperature readings becoming unreliable or invalid
XID transducer selection improvements
Digital depth number locks onto the surface clutter and not recovering*
Improved time to reacquire the digital depth number when lost*
Updated XID frequency selection for Airmar B175 family of transducers
Improved BSM ability to retain user settings after a power cycle*
* Requires accompanying update for Simrad displays
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3. High CHIRP Performance
The sensitivity of High CHIRP has been increased
Many users reported having to turn their Gain settings down when using High CHIRP, especially when used in conjunction with low sensitivity CHIRP transducers, this has been improved in the 3.8 version
High CHIRP with v2.0.0
High CHIRP with v3.8.0
High levels of noise in the water column with Gain set at 20
Auto Gain used without any bias
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Low CHIRP Performance
New sensitivity measurements have been implemented for less sensitive transducers
When using Low CHIRP with software version BSM-2/3 would apply the same amounts of gain to highly sensitive transducers (ex. R509LH) as it would to less sensitive transducers (B175L). Often this would cause Low CHIRP to miss fish targets that should have otherwise been visible.
Low CHIRP with v3.8 in 1,375ft
Low CHIRP with v2.0.0
Fish targets-not noise
Auto Gain used without any bias
Auto Gain used with +10 bias
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5. Improvements to Digital Depth Tracking
BSM-2/3 now has improved ability to hold and reacquire a digital depth
It is expected behavior for the digital bottom lock to be lost when turbulent water is run across the transducer. If the water is turbulent enough the sonar signal may be completely blocked and the BSM may lock onto that clutter. Software version 3.8 will better allow BSM to automatically regain the correct depth
In addition, the time to reacquire the digital bottom has been dramatically improved over v If at any time the digital depth number is lost, recovery time should be within a few seconds.
Time to reacquire can be improved by making sure the Search Depth in the installation panel is set correctly. Setting the Search Depth to ‘Unlimited’ will take the longest time to reacquire since it searches all of the available sonar information for the digital depth.
* Requires accompanying update for Simrad NSS evo2 and NSO evo2 displays
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Temperature and XID
Several customers have reported issues with temperature and Airmar XID
These include
Temperature disappearing from the sonar image
Temperature going to 131oF (55oC) and locking there
Airmar XID not recognizing transducers properly
Incorrect frequency selections when transducers are identified correctly
Each of these has been corrected
Problems with temperature and XID readings are a result of the digital XID circuits inside the transducer locking up and no longer responding. With software version 3.8, BSM-2/3 can now reset the XID inside the transducer to restore it to a usable state.
The available frequency ranges for each compatible transducer have been updated
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Airmar transducers
All transducers have a period of testing to be completed before being approved for use with Simrad sonar products.
The transducers that have been approved by Simrad R&D have been given part numbers and can be ordered directly through Navico.
In addition, ordering transducers through Navico is the best way to ensure they ship with the appropriate connectors for your application.
We have made the switch with Airmar to now ship all transducers with connectors- you will see an end to bare wire transducers as the stock is cleared out and turned over.
Simrad does still offer the connector to bare wire adapter for retrofitting transducers.
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8. Performance Screenshots

9. Fishing the Upper Water Column
Using High frequency sonar to see fish targets near the surface in 1400ft depth
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10. High Speed Performance
High CHIRP at 23kts
Fish Targets
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Fishing Dropoffs
Using High CHIRP and 60kHz to track fish off a steep drop off
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Availability
BSM-3 RTM 3.8 is available now
BSM-2 RTM 3.8 is available now
Download from
There are separate updaters for BSM-2 and BSM-3. Please ensure you download the correct version for the equipment installed on your vessel.
Several software fixes also require downloading and updating your Simrad NSS evo2 or NSO evo2 display- please check the download page and update your display along with your BSM module
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13. © Navico Company — CONFIDENTIAL