Propeller guard?

Mirror Painter

Mirror Painter

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I apologise in advance because I am certain this has been discussed many times and probably recently too. But what about propeller guards? I've been reading the YBW online article about the coroner's comments following that dreadful accident. And then the follow on comments about whether the RYA approve of prop guards or not.

My question is selfish and simple - on my tiny cabin cruiser on the Thames, where the long shaft engine does grind the bottom on occasion during drought, is there any good reason for me NOT to fit a prop guard?

Thanks.
 
I would guess that on a non planing hull, the benefits of a prop guard would outweigh the down sides.
When I bought my RIB new, the dealer threw in a prop guard, and it came already fitted. I used it like that for at least four years, but was never really satisfied with the performance. I had a eureka moment one day when I coincidentally had the time to act, and I removed the guard. The result was 6.5 knots on to the top speed, less stress on the engine and improved fuel consumption. The blurb that I had read at the time that I bought the RIB stated that thrust would be improved and fuel consumption also would be better with a guard. This I can tell you from experience is rubbish.
For safety boats working in and around dinghy fleets though, they probably are a good idea. For fast planing RIBs, I would suggest that a prop guard is not a good idea,but safety lines to help prevent crew going overboard would make sense.
CJ
 
Prop guards on the RIBs on Stavros, as one of their roles is MOB recovery. Apparently they take a big chunk out of the performance though - not surprising really when you look at them.

Pete
 
Prop guards and performance...
th
 
Many years ago I was doing a catamaran instructors' course at Plas Menai. Their rescue ribs had recently been fitted with prop guards to satisfy newly introduced safety requirements and the instructors complained bitterly about the loss in performance. The guards were heavy affairs, with a long, tubular shroud and thick wire mesh, so not as lightly built as Neil_-Y's photo shows.
 
Moxon said:
I apologise in advance because I am certain this has been discussed many times and probably recently too. But what about propeller guards? I've been reading the YBW online article about the coroner's comments following that dreadful accident. And then the follow on comments about whether the RYA approve of prop guards or not.

My question is selfish and simple - on my tiny cabin cruiser on the Thames, where the long shaft engine does grind the bottom on occasion during drought, is there any good reason for me NOT to fit a prop guard?

Thanks.
Click to expand...

There is currently a poll thread on Motor boat Forum about prop guards, may answer some of your queries. http://www.ybw.com/forums/showthread.php?348463-Where-do-you-stand-on-prop-guards
 
Think the question in your case might be Why should I fit one? You are unlikely to be boating in places where there are swimmers in the water. As other posts and the thread running on the other forum suggest the benefit is on boats that regularly operate near people in the water such as dive boats and ski boats plus high speed craft like RIBs where there is a greater chance of somebody going overboard - as happened in the case that started the current debate. However, as also pointed out there is a significant loss in performance in many cases.

There may be some benefit in inland waterways in protecting the prop from debris, but not sure that compensates for the potential performance loss.
 
Thanks for the replies and the link to the other thread.

Tranona, you say 'You are unlikely to be boating in places where there are swimmers in the water' - all I can say to that is David Walliams has a lot to answer for.

Edit to add - the world's best boat does have a planing hull actually. She just doesn't get it out these days :-)
 
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Propellor Guards....the manufacturers make all sorts of claims about them, like improved fuel consumption, improved manoeuvrability etc. However, over the last 6 years as Bosun of my yacht club and a safety boat driver for a fair number of years I would dispute the claims made, also I would dispute the safety aspect as regards swimmers in the water. With one exception, and that is the type of guard fitted by RN diving support RIBS, which is a substantial (in effect) cage surrounding the prop. They do protect people in the water.

The usual Prop guard available consits of a Plastic Tunnel which encloses the prop, thís has the effect of channeling the water, together with any debris, past he prop. The debris can consist of substantial bits of wood whch can damage the prop, and also smash the plastic prop guard. I have seen that quite often. From that, you could surmise that such a 'tunnel effect' could suck in someones foot.

I queried the use of prop guards on safety boats a few years ago with the RYA to see whether the agreed with my reasoning. As a result of their replyI removed all the prop guards on all the club safety boats, and we concentrated instead on good boat handling skills. The main one being that if any one was in the water abaft of the driver then engine was stopped. When approaching someone in the water, providing you pck the up from a pint forward of the driver then the caualy wil be at least 4 metres away from the prop and at the point of pick up the engine should be stopped (always)
 
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