How does the C rating effect boat performance

[KartRacer]

Not sure I understand the need for higher C rating in the boat arena. I run high C rates in off road truck for punch. Does that equate to higher horsepower or torque from stop. If it is torque then a higher C rate should produce higher top speed. If this is so are we talking significant difference or just needed in the racing environment.
Starting build on a Delta Force Pirate 35" Mono with Leopard 4082 and Seaking 180 on 6s power.

Thanks in advance for your comments .

[Fluid]

First, there is no standard for identifying the "C" rating of LiPo cells. One company's 45C is the same as another company's 25C. But assuming that the "C" ratings are accurate, the higher the "C" rating the less internal resistance and the more power is available for the motor to draw from. You cannot compare boats with trucks - put that out of your mind entirely! Boats draw high amps all the time, unlike cars and truck which you can back off once the desired speed is reached. You will burn up equipment if you don't understand this - I have watched car guys do this for over 20 years.

However, if you are running a low amp setup like and RTR boat with stock motor then even with a large prop you are probably pulling less than 100 amps. Lower "C" rated cells can work fine for this application. But if you are building an open boat with amp draws between 150 and 200 amps, 25C cells will overheat and burn up - again, I've seen that happen too many times. If it were me, I'd not buy cells with less than an indicated 45C. That way even if the number is inflated it should still be okay for most uses.

Below is a 25C pack which was run in an open-motored boat pulling around 140 amps.
DSC00029.jpg

[KartRacer]

Thanks fluid. Makes sense, did not consider that the boat will draw constant amperage.
So to clarify, running the 4082 with the seaking 180 on 6s, ( 2-3s packs 5000 mah ) a 45C rated or above should be fine.
How does a #10 wire handle the amp draw? Charts I looked at say 45 amps on #10 wire. Am I missing something here.
Thanks again ,trying to avoid too many expensive incorrect decisions.

[ray schrauwen]

Below is a 25C pack which was run in an open-motored boat pulling around 140 amps.
[ATTACH=CONFIG]83311[/ATTACH]

Hey that looks like it came out of my 40" mono last month! What a mess and a dumb mistake on my part, 25C crapola.

[ray schrauwen]

#10 wire is just fine for your application.

Thanks fluid. Makes sense, did not consider that the boat will draw constant amperage.
So to clarify, running the 4082 with the seaking 180 on 6s, ( 2-3s packs 5000 mah ) a 45C rated or above should be fine.
How does a #10 wire handle the amp draw? Charts I looked at say 45 amps on #10 wire. Am I missing something here.
Thanks again ,trying to avoid too many expensive incorrect decisions.

[KartRacer]

Thanks Ray

[lectriglide]

Thanks fluid. Makes sense, did not consider that the boat will draw constant amperage.
So to clarify, running the 4082 with the seaking 180 on 6s, ( 2-3s packs 5000 mah ) a 45C rated or above should be fine.

What KV motor are you going to run on 6s?