Propellor guards

[pete stiff]

Hi,
At a recent club meeting, the topic of guards for props was raised during a discussion on risk assesment, and a member mentioned that these were available. Just wanted to know if anyone has any experience of these or any advice to offer.
Best Regards
Pete

[Andy Wade]

Hi,
At a recent club meeting, the topic of guards for props was raised during a discussion on risk assesment, and a member mentioned that these were available. Just wanted to know if anyone has any experience of these or any advice to offer.
Best Regards

Well, we used to have some of these, and they just collected seaweed, and reduced the efficiency of the engine (even stopping the boat from reaching the plane a few times) and generally being a pain in the *ss.
IMHO it's better to make sure that all boathandlers are proficient, and all divers are well trained in procedures for ascending when there's boats skimming around, 'A' flags, dsmb's etc, good surface cover by the dive boats and vigilance by boat crew for bubbles and blobs.
I'd say they weren't a sufficient gain in safety for the trouble we had with them.
We also never had a diver/prop incident either, with or without the prop guards.
Of course, we have hit quite a few rocks with the prop blades over the years, so maybe we could have saved some money on replacement and repaired props along the way?

Just my 0.02p worth.





.

[John Williams]

If it's an issue ...why not consider moving away from propeller driven craft to jet-drives?

There's no risk of getting slicd by a prop...and there's also no risk of knocking the blades off the prop if you back into a rock (you might give the jet "nozzle" a whack - but this wont render it unusable for the trip home)

John

[Steve L.]

Pete

If I were you I would speak to someone who knows a bit about outboards. We brought a second hand inflatable and engine which had a prop. guard. We were told by the guy who serviced it that the guard puts a lot of stress on the propeller gearing and bearings and will prematurly cause excessive wear depending on the amount of use.

Steve

[Richie771]

Have you seen the Guy down in Portland Bill with the 'Flying Rhib'

He has no need for prop guards!!!

High Entry Techniques need to be mastered though

[scott laddiman]

Hi,
At a recent club meeting, the topic of guards for props was raised during a discussion on risk assesment, and a member mentioned that these were available. Just wanted to know if anyone has any experience of these or any advice to offer.
Best Regards
Pete


I once got hit on the back of my tank by a prop. The club decided to fit prop guards. It then found this slowed the boat down so removed them.......... I am no longer a member of that club!

Scott.

[pat farrell]

:=Hi,
:=At a recent club meeting, the topic of guards for props was raised during a discussion on risk assesment, and a member mentioned that these were available. Just wanted to know if anyone has any experience of these or any advice to offer.
:=Best Regards

Well, we used to have some of these, and they just collected seaweed, and reduced the efficiency of the engine (even stopping the boat from reaching the plane a few times) and generally being a pain in the *ss.
IMHO it's better to make sure that all boathandlers are proficient, and all divers are well trained in procedures for ascending when there's boats skimming around, 'A' flags, dsmb's etc, good surface cover by the dive boats and vigilance by boat crew for bubbles and blobs.
I'd say they weren't a sufficient gain in safety for the trouble we had with them.
We also never had a diver/prop incident either, with or without the prop guards.
Of course, we have hit quite a few rocks with the prop blades over the years, so maybe we could have saved some money on replacement and repaired props along the way?

Just my 0.02p worth.

They seem to work fine on the surf rescue boats in cornwall.



.

[Andy Wade]

:=:=Hi,
:=:=At a recent club meeting, the topic of guards for props was raised during a discussion on risk assesment, and a member mentioned that these were available. Just wanted to know if anyone has any experience of these or any advice to offer.
:=:=Best Regards
:=
:=Well, we used to have some of these, and they just collected seaweed, and reduced the efficiency of the engine (even stopping the boat from reaching the plane a few times) and generally being a pain in the *ss.
:=IMHO it's better to make sure that all boathandlers are proficient, and all divers are well trained in procedures for ascending when there's boats skimming around, 'A' flags, dsmb's etc, good surface cover by the dive boats and vigilance by boat crew for bubbles and blobs.
:=I'd say they weren't a sufficient gain in safety for the trouble we had with them.
:=We also never had a diver/prop incident either, with or without the prop guards.
:=Of course, we have hit quite a few rocks with the prop blades over the years, so maybe we could have saved some money on replacement and repaired props along the way?
:=
:=Just my 0.02p worth.
:=

They seem to work fine on the surf rescue boats in cornwall.

Good point, but there's a bit of difference between a surf rescue boat with a couple of lifeguards and a casualty inside and a club boat with 6 fully kitted divers in it, plus the surf rescue guys may have to comply with health and safety regs, so may be required to have prop guards.
Prop guards aren't that common on dive boats in my experience and it's probably because they reduce the efficiency of the engine too much.
John Williams' suggestion of using a jet drive engine is probably the best option if there's a strong desire to improve safety - on top of ensuring proper boat handling safety measures.

Actually, come to think of it, I'm quite surprised that the surf rescue guys don't insist on jet drives on all their boats.

[Andy Wade]

[simon brookes]

There are a number of issues here;
Prop guards will slow the boat
The more efficient "schultz nozzle" guards in polyproylene do break on contact with v. hard objects like rocks so are in effect sacrificial.
Outboard jets though very safe lose about 25% of their shaft horsepower.
If you look at Yamaha's 80hp jet drive the motor is actually a 115hp unit so you burn more fuel.
Deep vee RIBs arent ideally suited to outboard jets flatter bottomed craft make more use of the jets characteristics. If you decide to move on to an inboard jet you then start talking about alot more expensive hardware and loss of space for divers. If jets were the best option they would have been heavily promoted to us as divers and bigger operators like the RNLI would fit them as standard.
I have yet to hear from manufacturers as to the optimum pairing of hull type and jet but have not ruled them out, they reduce risk but at a penalty.

Simon.