The Multi-Vu HD utilizes HDMI video-out and the signal will need to be converted to RCA for use with most sonar systems. This conversion will change the video signal from HD to standard definition. You would accomplish this by ordering an HDMI to RCA adapter online. See below link for adapter ordering links.
https://www.amazon.com/gp/product/B06X9YSC3C/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1