B744VC-VLC Transducers

This page describes the newer versions of the B744V and B744VL transducers, sometimes called the B744VC and B744VLC. These versions replaced the previous models in 2009. The newer versions have a second retaining cap and do not have a clevis pin through the top.


The B744VC and B744VLC transducers are not mix and match transducers. They all have a fixed 10-meter cable attached and cannot easily be used with brands of equipment other than the one they were made for. Some adapters are available.


The depth and temperature sensors are located inside the bronze body. The transducer measures speed by using a magnetic paddlewheel which triggers a Hall effect integrated circuit inside the bronze body.


If your speed sensor is not functioning you should first check that the paddlewheel is intact and turning freely. Damaged paddlewheels can be replaced using the kits below.


If the speed insert is damaged, it can be replaced with one of the speed-only inserts.


If the speed function is not working, but the paddlewheel and insert seem intact, then you will need to install an active insert that contains replacement speed and temperature circuitry as shown below.


You will also need to use an active insert if the temperature sensor has failed.


The active inserts have a cable attached and this is to be spliced into the existing transducer cable using the junction box provided. Instructions are included.


If the depth sensor fails, the transducer must be replaced.


Before calling or emailing us about parts, make sure you have the Airmar part number from the label on the transducer cable (31-xxx-xx). Note that all measurements shown are from the very top to the very bottom of the black plastic body.

B744VC

B744V showing top cap
B744V with high-speed fairing

B744V with high-speed fairing
B744VL long-stem version

B744VL long-stem version
33-590-01

Speed insert for B744V 33-590-01
33-551-01

Blanking plug for B744V 33-551-01
33-113

Paddlewheel for B744V 33-113

Speed Insert Dimensions
B744V

Blanking Plug Dimensions
B744V

Blanking Plug Dimensions
Long-stem B744VL

Available Parts

Part Part # Type Description
33-590-01 Speed-only insert For all B744VC models. Length 6.96"/177mm.
33-590-02 Speed-only insert For all long-stem B744VLC models. Length 9.33"/237mm
33-113 Paddlewheel kit For both B744VC and B744VLC, containing one paddlewheel with shaft, and 4 O-rings
33-535-01 Complete paddlewheel kit For both B744VC and B744VLC, containing one paddlewheel with shaft, 4 O-rings, 1 valve assembly and 2 pull rings
33-551-01 Blanking plug For all B744VC models. Length 6.58"/167mm
33-551-03 Blanking plug For all long-stem B744VLC models. Length 8.99"/228mm
02-030 Bronze hull nut For all B744VC and B744VLC models
04-234-1 Plastic lower cap nut For all B744VC and B744VLC models
04-565-02 Plastic top cap nut For all B744VC and B744VLC models
33-476-01 High-speed fairing For all B744VC and B744VLC models. The forward bolt and yellow cap are included.
33-443-01 Forward bolt kit For all B744VC and B744VLC models. Contains the forward bolt and yellow cap for the fairing.
B744VC-INS-JB Speed and temperature insert For B744VC used with all equipment except Raymarine, Lowrance and Navman.
B744VLC-INS-JB Speed and temperature insert For long-stem B744VLC used with all equipment except Raymarine, Lowrance and Navman.
B744VC-INS-BL Speed and temperature insert For B744VC connected to Lowrance or Simrad equipment that uses the Lowrance 7-pin blue connector.
B744VLC-INS-BL Speed and temperature insert For long-stem B744VLC connected to Lowrance equipment that uses the Lowrance 7-pin blue connector.
B744VC-INS-RAY Speed and temperature insert For B744VC connected to any Raymarine fishfinder.
B744VLC-INS-RAY Speed and temperature insert For long-stem B744VLC connected to any Raymarine fishfinder.
B744VC-INS-ST Speed and temperature insert For B744VC connected to Raymarine ST instruments
B744VLC-INS-ST Speed and temperature insert For long-stem B744VLC connected to Raymarine ST instruments