[CA] [CA11] Polars now in Lighthouse

[Chuck - Raymarine - Moderator]

John,

Q1: Since we have seaweed issues where we sailboat race STW transducers are problematic due to fouling which is why none is now installed. Is it possible to use speed over ground (SOG) to display laylines instead of STW. This would be best because of both fouling of speed transducers and poor quality current data in our area in navionics and other chart apps.
A1: Negative. Please note the entry in the polars is based upon True Wind data. As indicated within the FAQ addressing the subject of True Wind calculation, speed through water (STW) data is required.

Question 2: If Lighthouse 3 laylines/startline/polars cannot be made to work without STW what STW transducer (no depth needed) would be easiest to interface with my Axiom 9 RV? (I purchased the Axiom 9 RV and RV transducer to also use on my powerboat which we use for fishing).
A1. With the exception of 50kHz/200kHz fishfinder transducer featuring a paddle wheel and 50kHz/200kHz fishfinder transducer joined to a fishfinder speed/temp transducer, no STW transducers may be directly interfaced to the Axiom RV MFD. As MFDs running the latest LightHouse 3 software can calibrate (multi-point calibration actually) speed transducers which have been interfaced to an iTC-5 Analog Instrument converter, it would be recommended that an iTC-5 be installed as a backbone component of the system's powered and properly terminated SeaTalkng / NMEA 2000 backbone and that an Raymarine’s web siteanalog instrument thru-hull speed/temp transducer be interfaced to the iTC-5.