Wash/Duo-props on inland waterways

[D3B]

Hope this one doesnt start big arguments about should or shouldnt be there!
I am still quite new to this boaty stuff....but love every minute. hence going from Freeman 24 to Sealine S23 and now waiting for delivery of SC29...hopefully mid-April. Done most of the courses and really want to get on the big blue stuff as soon as possible. trouble is a lot of my time will be spent poddling up and down the River Ouse...the real one in Cambridgshire not that funny northern one /forums/images/graemlins/laugh.gif. there lies the told problem.
i have many friends who spend there time in all types of boats gently bobbing up and down the river......but one keeps niggling about the wash and the effects duo-props have on the vegitation and banks in the river. he has gone from complaining about my wash in the S23, which on the one occasion i showed off, was not nice. that taught me i would have to keep below the 7 mph speed limit otherwise i would be upsetting too many people. wash problem solved!
those of you that know the area will be aware that the "Old West" is quite narrow and shallow and has lots of weed growth during the summer. with a speed limit of 4 mph i dont have a wash problem. this (actually very good friend) is now niggling that the duo-prop will be cutting up the weeds and disturbing the bottom so much that it becomes a hazard to other boats following, which get the debri sucked into their filters.
help!!!
i am wondering if this friend is actually jealous or has a genuine point.

 

[danielbroad]

I spent a season on the Great Ouse with my old Bayliner once.

I did strike the bottom quite often as its not that deep in places - but thats more of a hazard to the state of your prop than anything else. It always just seemed fairly "gravelly" where i was.

Whilst i don't think the Great Ouse is well suited to deep v / outdrive boats i don't see that a duoprop is any different to a standard prop is this manner.

River boaters (actually all boaters..) should be well used to checking their water strainers for weed so i don't see a problem.

 

[Roy]

If your duo prop is twin enginined you will never keep to 4mph or knots as it does more than that on tickover and you would have to keep going in and out of gear - not good over the long term for the boat.. Perhaps single engine will be ok and do 4 or 5 without gear in/out.

 

[stelican]

A friend of mine keeps his similar boat on the river .He has removed the outer duo prop which has decreased his speed slightly and of course if he touches the bottom hes only damaging one prop

 

[whisper]

Another option may be to drive with the trim all the way in and the trim tabs down. This may help to lift the stern, though as he is only going at 4 mph the effect might be marginal. Having the tabs down should also help him to go slower.
Think that the "weed" argument is far fetched and I reckon he needs some different friends /forums/images/graemlins/wink.gif

 

[lanason]

I think you should not use the boat at all.

My boat is still rocking from the last time you were out on the river and I'm miles away down near St Ives .........