[CA] [CA11] Sonar upgrade for Gs165 MFD - High speed, Planing hull

[Drifter2]

I am looking for help selecting gear for a Sonar upgrade.

I currently have a CP100 with and unknown transducer connected to my Gs165 MFD.
The boat is a 55 foot, Fiberglass, planing hull maxing out at about 40kn.
Currently over about 17kn I loose depth.
I want to upgrade the Transducer and Sonar Module to a more powerful setup to try to maintain a depth reading at higher speeds. The main need is for safety of navigation at higher speeds, not so much for fishing.
Can you please recommend the best transducer and module for me? Cost is not an issue.
Ideally a transducer that will fit in the same [censored] if possible.

Thanks

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Drifter2,

The CP100 was designed for use with DownVision and CPT-S transducers. For the benefit of others who may be viewing this thread, should the electronics support DownVision sonar imaging as well a high CHIRP Sonar imaging, then a DownVision transducer has been interfaced to the CP100. However, should the electronics only support high CHIRP Sonar imaging, then a CPT-S transducer has been interfaced to the CP100. Both of these types of transducers are available in thru-hull and transom mounted designs. With a vessel of this length and inboard propulsion (assumed) it is likely that the thru-hull version of one of these transducers was installed. Please click here to view a FAQ addressing how one may positively identify the transducer. In your case, it appears that the thru-hull DownVision transducers has been installed.

If the vessel's hull is less than 1" thick in the potential transducer mounting location and has been constructed solid fiberglass (i.e. no core materials), then I would typically recommend that the currently installed CP100 and transducer be left in place and that a CP370 w/A66089 M260 In-Hull Transducer be installed inboard or outboard of the installation location of the currently installed transducer. I have held bottom at speeds in excess of 40kts with the M260 and a DSM300 (predecessor of the CP370) on my own boat.