down speed?

[tlr426]

So I went to a local seminar and the captian that was giving the presentation says he does not reference is down speed to his sog... He said that he goes by the down speed on his probe and when he gets information about down speed he needs to know what unit the operator is using so he can extrapolate that data for use with his unit. He metioned that the fish hawk reads higher then the sub troll and the depth raider. My question is when reading about down speed in keatings books do I need to know the unit he was running or have these numbers been translated to sog as the reference speed. Its easy enough to drop the probe and see that it runs .2 or .4 mph faster and just subtract for calibrated speed... The question I ask is what do you guys do on your boats. I just got a fish hawk over the winter and I would like to optimise its productivity.

Edited March 1, 2015 by tlr426

[J.D.]

For me it's about repeatibility, not the actual down speed.  Down speed is no more than a reference point .

 

If my rods are flying with my probe showing 2.3, I keep running at 2.3. I don't care what the acutal down speed is, or what my SOG is. When you change direction in the Lake O. currents, Adjust your throttle to get back to the 2.3 downspeed reguardless of SOG. I don't care if my probe speed is "calabrated" or not.... just repeat the number that's catching fish.

 

 

 

Just my $.02

Edited March 1, 2015 by J.D.

[Sk8man]

I fully agree with JD The actual speed will vary according to many different factors. It is a "relative" measure in this situation (fishing) so no matter how you record it  on the device you are using...it really applies only to that specific situation... so whatever is working for you with that particular setup is what you want to repeat. For example you could have 2.3 at the probe and the guy right next to you with the same unit could have different readings because of many factors such as differences in current at his specific position, calibration issues, maybe the thickness of the cable of the downrigger and weight etc. etc. The critical thing is to know your own unit, keep track of best results with what equipment at the recorded speeds on that unit, and understanding that it is all really "guesstimation" so repeatability is really the only true measure for success. Reports of speeds from others boats in other situations should be at best considered as "estimates". This would apply whether talking about SOG, impeller based readings, or the various probe measures for down speed it is still all relative.

Edited March 1, 2015 by Sk8man

[baitrigger]

Everything stated is dead on. The fish hawks seem to run about .5mph higher. 2.5-3.3 on our x4 for steelies and kings. 1.2-2.2 for lakers and browns. The books you're refering to were writen before the hawk. General rule subtract .5mph. Good luck.

[finsntins]

yep.what they said. :yes:

[tlr426]

Thanks guys

[capt ace]

You can calibrate your Fishhawk's speed as well. We have ours calibrated so it matches the Moors and the Cannon SNT which run about the same. Typical X4D's run about .4 mph faster than the others out of the box. Being the same helps when wanting to dial in on a speed thats producing on one of your buddies boats or visa versa.