Welcome to the Humminbird Side imaging Forums woodsman1977.
We (Humminbird) are building the HELIX 5 models as fast as we can! Hope you won’t have to wait too long for yours.
The XNT-9-20-T transducer will work with the HELIX 5 SI-GPS model unit, however if you are planning on installing this inside-the-hull of a kayak, might I recommend the use of the MHX-XMK Kayak Transducer Mounting Kit? Since this transducer has a built-in temperature sensor the unit will recognize that the transducer is connected but will not know which transducer it is (it will try and work like the XNT-9-Si-180-T Compact Side imaging transducer).