[CA] RV Transducer(s) placement help

[Chuck - Raymarine - Moderator]

Scott,

Q1. Option 1 place the rv 220 set forward, where the head through-hulls are and move those back a foot or so. This will move the transducers below where the helm is, see photo. This location will experience a higher likelihood of being out of the water in moderate and above seas when planing. (moot point if these only work at trolling speeds as the faq seem to indicate) I am assuming trolling speed is 8-10 mph or lower?
A1. Trolling speed is within range which you have specified. However, at trolling speed, there is also little or no aeration of the water beneath the hull. Aeration generally begins at higher speeds. Accordingly and as long as you will be satisfied with using the B744V at higher speeds (assumes that the B744V currently performs well in its present location, then you may want to consider Option 2, as it will likely provide the RV transducers with deadrise which is within the range which they were designed to be installed.

Q2. Option 2 is to locate the pair in the stern and relocate the live well/ wash down water intakes aft or out bord of the transducers. I will still have to deal with the potential of the head through hulls disturbing the water.
A2. See the response to Q1.

Q3. Is there a hierarchy of location preferences in relation to through hulls? i.e is outboard of the transducer preferred to inboard?
Q3. It is recommended that the RV transducers be installed inboard of the B744V.

Q4. Is farther back on the boat preferred to closer to the bow.
A4. Yes.

Q5. Does clean water at trolling speed trump a more aft location?
A5. Clean water and not separating the RV transducer by too great of a distance are the most important considerations.

Q6. I have seen the diagrams on placement but they do not include discussion of forward through hulls.
A6. In spite of no specific directions to the contrary, through hulls, steps, etc. located forward of the transducers may (and most likely will, particularly if they are directly in line with) will cause an aerated flow of water across the face of the transducer at speeds above trolling speeds, preventing their proper operation at such speeds. The size, shape, and other physical characteristics of such objects is s determining factor in the speed at which they will trail an aerated flow of water.


Q7. Place the transducers between water intakes and the transducer flats.
I am concerned that the inlets may cause problems, partly because they are inboard of the transducer. I would think air will migrate to the surface from the keel up so any transducer inboard of an intake would be less likely to have aerated water interference.
A7. See the response to Q1. I would recommend moving the intakes aft.