Prop shaft rope cutter

[daletournier]

Hi, any suggestions regarding prop shaft rope cutters that can be fitted while boat is in the water?


Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[GordMay]

You might be interested in this.
➥ Propeller rope cutter test

[Jason Flare]

I have a prop-protector on our current boat and had one on our previous boat.

I test it each year by backing over my dinghy painter.

[Ziggy]

Originally Posted by daletournier

Hi, any suggestions regarding prop shaft rope cutters that can be fitted while boat is in the water?


Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

Take a look at the Shaft Shark (AB Marine - Shaft Shark - Propeller Protection Device). I don't think it's the most effective design, but it looks like it's a split serrated disk that would be very easy to install in the water.

[Symphony]

Originally Posted by Jason Flare

I have a prop-protector on our current boat and had one on our previous boat.

I test it each year by backing over my dinghy painter.

Ha! Excellent

[goodnumbers64]

I have had a shaft shark. It needs to be mounted very close to the prop. If your shaft is tapered, they will work with you to customize it for a nominal charge. It can be easily installed underwater.

[val99]

+1 for the shaft shark. Gets me thru kelp but have to go into reverse sometimes to clear any remaining stuff. Had it for 4 years.

[S/V Alchemy]

Originally Posted by Ziggy

Take a look at the Shaft Shark (AB Marine - Shaft Shark - Propeller Protection Device). I don't think it's the most effective design, but it looks like it's a split serrated disk that would be very easy to install in the water.

That's what we have. We didn't install it in the water, but I bought it considering that I could do so if I had to.

Does it work? I dunno, which means yes. At haulout, I found a tiny filament of polypropylene on one tooth. Did it therefore actually slice a length of line that would have otherwise bound my four-bladed VariProp in very cold water? Dunno.

I'm rather glad I don't know, when I reflect on it.

Just be prepared for some "sticker shock".

[JD-Odyssey]

I installed a Shaft Shark a few years ago. It may work well for kelp and some type of snagged lines but this Fall, my dinghy painter got sucked under the hull and wrapped around the prop (use propylene painter but still got sucked under). I had to dive in 50 F degree water in a shorty wet suit to free up the shaft... major shrinkage and an hour to warm back up. So, if you install one, don't let it give you a false sense of security.

I'm sure it does its job and works fine for a lot of different situations but it won't guarantee that you won't get snagged on something at some time.

[SV Bacchus]

Originally Posted by S/V Alchemy

Just be prepared for some "sticker shock".

Something I am now considering as a "must have" in SW Fl as I start plying my way south to the Keys. Lots of pots in the water and the associated line/bouy, which I do try to miss, but sometimes not so easy at night.

But why oh why, just because it is marine related, does it have to cost so much? Amazing that a SS bicycle gear (well, that is what it looks like) can cost so much. I get it, precision SS and yes, I will pay it.. Ugh!

[Steadman Uhlich]

Originally Posted by GordMay

You might be interested in this.
➥ Propeller rope cutter test

Gord,
That article and video is the best comparison I have seen yet on the prop line cutters.

Thanks for posting the link. I had seen some video on Youtube, but missed the full article, which I found very informative.

[SV Bacchus]

Originally Posted by JD-Odyssey

I'm sure it does its job and works fine for a lot of different situations but it won't guarantee that you won't get snagged on something at some time.

After viewing the video GM attached at the beginning of this thread I don't think any can give a 100% feeling of comfort but I feel it has to be better than nothing.

[Ziggy]

Originally Posted by JD-Odyssey

I installed a Shaft Shark a few years ago. It may work well for kelp and some type of snagged lines but this Fall, my dinghy painter got sucked under the hull and wrapped around the prop (use propylene painter but still got sucked under). I had to dive in 50 F degree water in a shorty wet suit to free up the shaft... major shrinkage and an hour to warm back up. So, if you install one, don't let it give you a false sense of security.

I'm sure it does its job and works fine for a lot of different situations but it won't guarantee that you won't get snagged on something at some time.

I agree. The Shaft Shark, like the other disk cutter designs, is not nearly 100% effective. This is supported by all the independent tests I've read. I have a similar design (Shaft Razor), and I still try very hard to avoid lobster pots and weed patches. I also carry a wet suit and a hook knife as a backup. Having said that, I haven't had a bad line wrap since I installed the Shaft Razor. I have had weeds collect on the prop, but they have much less effect on the thrust and they are easily cleared with a boat hook.

If you install a line cutter, I would also recommend carrying kevlar gloves to protect your hands in case you need to work close to it in the water.

[Steadman Uhlich]

I am curious, and I would like to see some cost comparisons on these products.
If anyone reading this has done some recent analysis, comparing the retail prices for the same size shaft but different prop line cutters, please post it or share or send me a PM. Note that the prices for these items can vary significantly based on prop shaft size, so it is important to quote same size.

[Pete7]

After 9 years we have just replaced the plastic bearing in our Ambassador stripper because the boat was out for a cutlass bearing change. Seems to work well and we have hit a couple of pots in that time. Also does a good job of cutting up the thin stringy seaweed mats that appear in the Channel after a storm. With bilge keels I wouldn't be without it as there is no keel to fend anything off.

Since we regularly dry out in mud between the tides the cutlass bearing and stripper do take a bit of a pounding with the mud.

Pete