Airmar CS4500 Part II (Reliable True Wind)

14 Responses

  1. Sandy Daugherty says:

    Lucid, Dan!
    But is the set and drift arrow in figure three going the wrong way? And can you not take the heading from the PB200?
    {Editor: drawing fixed on 11/3/2009}

  2. Ben Ellison Ben Ellison says:

    Good call, Sandy, and Dan’s humble editor missed it too! The set & drift arrow should be pointed the other way. Because COG & SOG are the vector sum of a boat’s motion thru the water and the water’s motion.

  3. SanderO says:

    Does the sonic speedo get screwy data from fouled hulls which which might shed rubbish? That is what give them inaccurate readings if anything? Can the be calibrated?
    What about the direction of the flow – must it be normal to the two ceramic sensors? What about the effect of a keel if you place it on the side and slightly aft of the leading edge?
    What are the outputs of the Airmar units? Is it universal? Sorry to be so dumb here,

  4. Dan Corcoran (b393capt) says:

    Sandy : The arrow is way wrong. I was so proud of this diagram, I will have to fix this! Thursday when I get home for sure. PB200 heading and GPS COG/SOG suffers a bit on the mast, Airmar has a new version on the way with additional axis of correction. The motion corrected wind is still A+++ in my book. I have a water level H2183 instead which I have an evaluation in front of Ben for comment. He is a a tough editor and mentor (no ego snacks), so don’t expect it soon.
    Ben: Wow, you missed that. I am still a novice, got to keep a sharp eye on me !
    SanderO: Within reason I have an answer. The CS4500 has worked well in the first year when the bottom wasn’t cleaned during the season (and was on the 2nd year of a 2 yr bottom coat) it wasn’t pretty at season end !, the 2nd year when it was cleaned every 8 weeks, and this last season when it was cleaned every 2 weeks and I could almost eat off it. No improvement over the three years, all seemed about equal in performance, although this last year I had the CS4500 under a microscope so to say as I was writing Part III of this series and testing with an ST70 speed pod and under said microscope noticed some jitter that some instruments dampen (like the ST60) and others don’t (like the data window in the e-series). It’s a small annoyance, but if you race boats you might want to hold out for the next version with the built in damping and more if your instruments don’t do it now.

  5. far_south says:

    On sailboats, adding the leeway vector completes the picture.
    Great article!

  6. Jeffrey says:

    I am currently trying to order one of these cs4500 from Gemeco and have been told they do not have any; they are going to try to build one for us. (I do not understad that half of the firms have nothing in stock and they expect boaters to purchase their equipment…execpt they do not have any ready to purchse)
    We already have the PB200 ready to install once boat goes into yard. We are going to add these along with two P79s for depth to a total retro fit of 1996 40′ Beneteau that was hit by lightning.
    This boat will have the new Simrad NSE-8 (got to test it out at IBEX…Wow) networkd with all IS20 Instruments, AIS 300 (now much lower priced) from Simrad and of course an AP2802 set up for auto pilot with a AP24 second head at the nav station down below. Simrad HD2k Radar will round out the set along with their BSM-1 depth sounder/fish finder thrown in for good measure.
    Will also have the black box from Mastry Engine to convert the 50hp Yanmar engine data to yet another LCD screen rather than the original Yanmar control panel which is dead. Data will show up on a Lowrance HDS-7 and also function as a total separate back up GPS unit.
    I for one cannot wait to see real true wind on boat instruments; this will be a real plus as the original RayMarine instruments never worked right after one week of use.

  7. Jeffrey says:

    I am currently trying to order one of these cs4500 from Gemeco and have been told they do not have any; they are going to try to build one for us. (I do not understad that half of the firms have nothing in stock and they expect boaters to purchase their equipment…execpt they do not have any ready to purchse)
    We already have the PB200 ready to install once boat goes into yard. We are going to add these along with two P79s for depth to a total retro fit of 1996 40′ Beneteau that was hit by lightning.
    This boat will have the new Simrad NSE-8 (got to test it out at IBEX…Wow) networkd with all IS20 Instruments, AIS 300 (now much lower priced) from Simrad and of course an AP2802 set up for auto pilot with a AP24 second head at the nav station down below. Simrad HD2k Radar will round out the set along with their BSM-1 depth sounder/fish finder thrown in for good measure.
    Will also have the black box from Mastry Engine to convert the 50hp Yanmar engine data to yet another LCD screen rather than the original Yanmar control panel which is dead. Data will show up on a Lowrance HDS-7 and also function as a total separate back up GPS unit.
    I for one cannot wait to see real true wind on boat instruments; this will be a real plus as the original RayMarine instruments never worked right after one week of use.

  8. Len Bertaux says:

    In order to consider changing over my B&G speed paddle and air instruments I need to know if they are compatible with the earlier NEMA standard used by my older B&G computer/autopilot. How can I find this out?

  9. bobc says:

    Len,
    You should be able to use the CS4500 and may be able to display wind information from the Airmar sensor but B&G will not use nmea wind in any calculations so it will be essentially useless for you.
    They have a support number where someone could probably give you a better explanation than I.
    try them @ 800 628 4487

  10. Dan Corcoran (b393capt) says:

    Raymarine has started reselling the CS4500 in combination with their DSM product.

  11. Richard C says:

    I spoke to an Airmar Tech support person a few weeks ago who told me they have a new, Depth, Speed, Temp transducer with N2k output that will be introduced this coming spring. I believe he said it may be called a DST-900. This is exactly what I’m looking for since I am in the process of abandoning all NMEA 0183 devices, (with the exception of a feed to the autopilot).

  12. Dan Corcoran (b393capt) says:

    Updated Entry – The true wind diagram has been updated to correctly reflect the direction of set & drift in figures 2 & 3.
    If you look back at Part I, there is also some new comments about how true wind is valuable to one sailboat owner while racing, to the extent he dosn’t even configure apparent wind to display on his instruments.

  13. bobc says:

    Dan,
    Most serious racers will prioritize in this order:
    TWD True Wind Direction is the most important number they have, period.
    Boatspeed, and targets
    Target Speed for upwind sailing
    Target TWA for downwind sailing
    TWS True Wind Speed for sail selection and to establish Targets
    Heading as a gut check on TWD
    Apparent Wind Angle, occasionally for steering but only upwind and also as an aid in determining wind shear
    Apparent Wind Speed, almost never as it is irrelevant to any decision making

  14. Dan Corcoran (b393capt) says:

    I am curious. Has this series of articles and/or the diagram above helped anyone? Has it encouraged anyone who day sails to see value in using true wind to judge the performance of their sailing and sail trim settings? Has anyone who sails become a convert from believing that GPS SOG is good enough, to now keeping your paddlewheel clean and using real boat speed ?

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