[CA] [CA11] Steering sailboat at most efficient angle to wind via autopilot

[Fatcatmax]

We have a 38' catamaran and we are planning to upgrade to an Axiom 9 chartplotter, an EV1 autopilot and other equipment as needed. We are completely analog right now (old E80) and upgrading to all digital. We want to equip the boat so that we may use the autopilot to sail the most efficient course (angle to the wind) with changing wind directions automatically. We do not know what equipment will be needed to accomplish this goal or if it can even be done. WE would apreciate comments and specifically if our planned new equipment (i.e., EV1 and/or Axiom 9) should be reconsidered. Right now we have analog wind and depth, but want to go digital. If we need additional equipment (we assume so), recommendations for specific equipment to accomplish our objective would be appreciated!

Thanks

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Fatcatmax,

The feature which you have described is wind vane mode feature which has historically been supported by Raymarine autopilots and continues with the Evolution autopilots. Wind vane mode will alter the course of the boat, modifying the locked heading to maintain either the current apparent wind angle or the True wind angle – either may be selected. During execution of the Dockside Wizard, Sailboat must be specified for the boat type. An Evolution autopilot for a sailing application consists of the following components:
- EV-1 CCU
- p70S autopilot control head
- ACUxxx - model of ACU is dependent upon the type of autopilot steering actuator which will be or has been installed onboard the vessel
- autopilot steering actuator ... this is dependent upon the weight of the sailboat or the characteristics of the steering system.

The system will require apparent wind input. If seeking new equipment, this may be accomplished by any of the following means:
- install an iTC-5 with analog wind transducer ... the Axiom MFD will be used to calibrate the wind transducer
- install an i60 Wind instrument w/analog wind transducer.

Should true wind data be desired, then it would be necessary to additionally interface the system to a speed through water data source. This may be accomplished by any of the following means:
- install an iTC-5 with analog speed/temp transducer ... the Axiom MFD will be used to calibrate the speed transducer
- install an i50 Speed or i50 Tridata instrument with an analog speed/temp transducer

The model of Axiom/Axiom Pro/Axiom XL MFD to be selected has no bearing upon the ability of the new system to support the features which you have specified. The Axiom MFD, iTC-5 / i60 Wind, and iTC-5 / i50 Speed/Tridata will each be interfaced as spurs to a powered and properly terminated SeaTalkng / NMEA 2000 backbone