B744V-VL Transducers

This page describes the older versions of the B744V and B744VL transducers, manufactured before 2009. These versions have a clevis pin through the top of the insert.


The B744V and B744VL 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. These older versions are no longer made, but the newer B744V and B744VL models can be installed without changing the original fairing.


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.

B744V

B744V showing clevis pin
Speed insert for B744V 20-752-1

Speed insert for B744V 20-752-1
B744VL long-stem version

B744VL long-stem version

Speed Insert Dimensions
B744V

Blanking Plug Dimensions
B744V

Blanking Plug Dimensions
B744VL Long-stem

Available Parts

Part Part # Type Description
01-591-KIT Clevis pin kit For both B744V and B744VL models.
20-752-1 Speed-only insert For all B744V models, and for B66V. Length 6.81"/173mm.
33-113 Paddlewheel kit For both B744V and B744VL, and for B44V, B66V, B66VL. Contains 1 paddlewheel with shaft, and 4 O-rings
33-218 Complete paddlewheel kit For both B744V and B744VL, and for B44V and B66V. Contains 1 paddlewheel with shaft, 4 O-rings, 1 valve assembly, and 2 pull rings
20-175-5 Blanking plug For all B744V models. Length 6.44"/164mm
33-483-01 Blanking plug For all long-stem B744VL models. Length 8.82"/224mm
33-476-01 High-speed fairing For all B744V and B744VL models. The forward bolt and yellow cap are included.
33-443-01 Forward bolt kit For all B744V and B744VL models. Contains the forward bolt and yellow cap for the fairing.
B744V-INS-JB Speed and temperature insert For B744V used with all equipment except Raymarine, Lowrance and Navman.
B744VL-INS-JB Speed and temperature insert For long-stem B744VL used with all equipment except Raymarine, Lowrance and Navman.
B744V-INS-BL Speed and temperature insert For B744V connected to Lowrance equipment that uses the Lowrance 7-pin blue connector.
B744VL-INS-BL Speed and temperature insert For long-stem B744VL connected to Lowrance equipment that uses the Lowrance 7-pin blue connector.
B744V-INS-RAY Speed and temperature insert For B744V connected to any Raymarine fishfinder.
B744VL-INS-RAY Speed and temperature insert For long-stem B744VL connected to any Raymarine fishfinder.
B744V-INS-ST Speed and temperature insert For B744V connected to Raymarine ST instruments.
B744VL-INS-ST Speed and temperature insert For long-stem B744VL connected to Raymarine ST instruments.