What RPM should I be cruising at?

[robtheplod]

15 hours ago, Tony Brooks said:

PS often the rev counters will "stick" at whatever reading it was showing the instant the engine/ignition was turned off. That is normal, it should drop to zero revs the moment the ignition is turned on again.

The question i keep forgetting to ask, answered... thanks Tony!

[NB Alnwick]

We usually cruise at 180 rpm on canals - less when passing moored craft and anything up to 350 rpm on rivers and estuaries where we have a decent depth of water. That said, I doubt if this is of any help or interest to the OP.

[Victor Vectis]

On 19/08/2023 at 18:07, Captain Pegg said:

This one was working brilliantly

 

 

SLOW DOWN!

😃

[blackrose]

On 16/06/2021 at 17:36, ditchcrawler said:

I still bet there is something wrong and it will go faster

 

I think so too. Lots of people here said that my 57 X 12ft widebeam was underpowered with its 55hp engine and the hull shape was the limiting factor so not much could be done about it.

 

I wasn't really looking for more speed but just a bit more power because it seemed to be over-propped, only achieving 1900rpm in deep water on the Thames from a 3000rpm engine. I later discovered that part of that discrepancy was due to an uncalibrated rev counter, however I also had the prop repitched and achieved an additional 400rpm (max 2700rpm calibrated) and now have a lot more power plus a bit more speed. 

 

It's certainly worth doing some prop calculations with a couple of the online resources and speaking to a company like Norris who repitched mine.

 

https://vicprop.com/displacement_size_new.php/?m=1

 

[Mike Todd]

I was about to add that the design of the swim can make a significant difference and the pic seems to show  a rather bluff one.