Question re hull designs that reduce risk of fouled props, keels or rudder

[coffsguy]

Hi all,

Along the coast of Aus we face huge issues with fish and crayfish traps, long liners and other debris (such as cut-adrift nets) that can immobilize or seriously damage cruising yachts. In some instances this is just an inconvenience but it can also have catastrophic results.

It seems to me that yachts with bulb (or wing) keels, exposed props or saildrives, and spade rudders, are not the ideal design even though they may be more efficient than full keelers that perhaps shed debris more readily.

My question to those blue-water cruisers with greater experience than mine is how much consideration do you give to choosing a hull design that reduces this risk?

I look forward to your comments and/or recommendations.

[44'cruisingcat]

One reason we decided on the daggerboard, outboard motor, kick-up rudder combination. And it's been tested a couple of times, on crab pots.

[Jim Cate]

My question to those blue-water cruisers with greater experience than mine is how much consideration do you give to choosing a hull design that reduces this risk?

While the hazards do exist, this factor was not a big consideration for us. The benefits of fin keel/separate rudder, for us, outweighed the worry about fouling floating debris. We've logged ~135,000 miles since we departed SF years ago, and have only once fouled a crab pot line (in lake Macquarie, NSW) in all that time. Perhaps we've been lucky with that result, but it is our experience. Oh... fouled our own dinghy painter once, long ago and before we switched to a floating line!

Obviously, other folks have a differing reaction to the potential hazard...

Jim

[Paul L]

Originally Posted by coffsguy

Hi all,

Along the coast of Aus we face huge issues with fish and crayfish traps, long liners and other debris (such as cut-adrift nets) that can immobilize or seriously damage cruising yachts. In some instances this is just an inconvenience but it can also have catastrophic results.

It seems to me that yachts with bulb (or wing) keels, exposed props or saildrives, and spade rudders, are not the ideal design even though they may be more efficient than full keelers that perhaps shed debris more readily.

My question to those blue-water cruisers with greater experience than mine is how much consideration do you give to choosing a hull design that reduces this risk?

I look forward to your comments and/or recommendations.

You've made a case based on local conditions and then asked the question of folks that are in different conditions - bluewater. In answer to your question, I'd say we had zero consideration. Any boat can get lines, etc tied up in a prop. We've cruised areas where you couldn't travel more that few miles without snagging a long line. These were off Guatemala west coast. They use a small black flag to mark one end of the line and a plastic milk jug to mark the other. These are maybe 50 meters or more apart and basically not visible at night or much in the swell during the day. You pick one up, stop the boat , get your knife out and cut it. Its just part of the game. A good sailing hull with decent performance is also just part of the game.

[Don C L]

Originally Posted by coffsguy

Hi all,

Along the coast of Aus we face huge issues with fish and crayfish traps, long liners and other debris (such as cut-adrift nets) that can immobilize or seriously damage cruising yachts. In some instances this is just an inconvenience but it can also have catastrophic results.

It seems to me that yachts with bulb (or wing) keels, exposed props or saildrives, and spade rudders, are not the ideal design even though they may be more efficient than full keelers that perhaps shed debris more readily.

My question to those blue-water cruisers with greater experience than mine is how much consideration do you give to choosing a hull design that reduces this risk?

I look forward to your comments and/or recommendations.

I'd say it depends where you are and your level of comfort with the trade-offs. In my area, kelp beds, crab and lobster pot buoys are pretty common, and I really like how my long keel slides over everything. But I also appreciate the overall strength of the hull with its molded in long keel. I like the way my boat performs though, yes, I won't do well up wind compared to a deep fin keel or turn as fast as a spade rudder. It's a matter of peace of mind I guess, if hitting things is a major concern, there are some very nice boats with long keels and attached or skeg-hung rudders that sail very well. My own concerns with spade rudders come not from snagging things so much but their strength.

[boatman61]

I sail the West coast of Europe and Med a lot.. lots of floats and pot marks but have yet to snag one.. usually my bow wave pushes it to one side and I sail/motor on by.. the only time I've fouled my prop was on a huge sheet of industrial plastic.. and just once had my rudder jammed by a free floating old buoy trailing a long line.. that I managed to free by heaving to and allowing wave action to free it.. the plastic I had to dive and cut free.. not easy..

[jtsailjt]

Full keels with an aperture for the prop, with a 2 bladed prop fitted and the shaft marked so it can be stopped with the prop in a vertical position, or a folding prop is the best for avoiding getting hung up on a warp. But my boat has a fin keel with a 3 bladed max prop with a (Spurs) line cutter on the shaft and I'd say I get hung up about once a year despite my best efforts to avoid lobster buoys. I used to get worried about it but it's not really a big deal. If conditions are calm and I think it's safe, I circle it to try to unhook it and if necessary I dive on it. But if I think there's danger in diving, I just fire up the engine and put it in gear which usually cuts the line off. If possible, before doing that I try to reach under the boat and grab the warp with a boat hook so I can re-tie the buoy onto it after my Spurs cut it. But often that's impossible so unless there's a second buoy on the line, unfortunately the lobster trap is lost. That's about $100-$150. So, I've picked up the cut off buoy and found the lobsterman it belongs to and offered to reimburse him for his lost trap and he just laughed and said it was the cost of doing business and don't worry about it. Since then, I've discussed it with several lobstermen and they feel the same way, expecting to lose a certain number of traps each season. They know it's also the last thing a sailor want to do is to get hung up on one so it's not like we're doing it deliberately.

I wouldn't base my choice of a boat too much on its capability to avoid picking up traps but if you'll be sailing in an area with lots of lines, make sure you put some sort of line cutter on the shaft so it's possible to cut a line off without exposing yourself to too much danger. Also, having a pretty long boat hook can be helpful to possible push the buoy down to help untangle it.

The one time I came closest to any danger from getting hung up was when a lobsterman put a trap almost under my boat on its mooring and then when the wind shifted my boat swung over it and the buoy and line became entangled in my prop. I couldn't see it as I approached my boat with 4 or 5 friends so we all hopped aboard, pulled up the dinghy on the davits, I started the engine and one of my friends on the foredeck dropped the mooring pennant just as the warp tightened around my prop shaft and stopped the engine cold. We were now "anchored" by our prop shaft to the lobster trap laying on the bottom and were drifting sideways in about a 15 knot breeze towards a boat moored nearby and restarting the engine in neutral and then shifting into reverse didn't help, so I grabbed the knife I keep at the helm and jumped in, untangled/cut the buoy free from my prop and climbed back aboard. It happened so fast that we were out of the harbor before my friends who had been on the foredeck noticed that I had taken a swim!

[robert sailor]

We sail a boat with a fin keel and partial skeg rudder with folding prop and don't give any considerations to modify our choice because of crab pots. Had a few issues over the years but nothing we were not able to look after.

[roverhi]

The Brewer designed Morgan 38 and S&S designed Allied XL42 have the ideal bottom to avoid pots for boats with a seperate keel and rudder. Both boats have a skeg mounted rudder with the prop aperture in the skeg. With the rake of the keel face and the skeg should shed most pot anchor lines easily and minimize the chance of fouling the prop. Other than that type of underbody, it's the good old keel attached rudder with a plate to keep any lines from jamming in the slot between the rudder and keel for coming home without dragging someone's livelihood behind. The boat with a torpedo bulb sticking out fore and aft off the keel look headaches are guaranteed. Wing keels look to be in the same boat.

Have sailed full keel boats and the only problem I've had with detritus is one time Kelp hooking onto the self steering vane servo rudder and the breakaway coupling doing its thing.

[TJ D]

We have a bulb keel, and it's a line catcher. I think that if I were going to cruise primarily in an area with a whole lot of crap in the water, I would probably make another choice. We didn't have a lot of fun in Maine. We only got hung up once, but we definitely paid a heck of a lot of attention.

Fortunately, many buoys that we've seen around the places we've cruised have a tapered lower end, so this helps them to slide off.

Maybe 6 times in the last 10,000 miles, we have had to round up, and let the boat drift backwards to get off some debris.

So, the bulb's a bit of a hassle. One thing that I've considered to rig temporarily is a wire from the tip of the bulb up to our bobstay fitting on the stem. I think that if we decide to cruise in a place with a huge amount of stuff in the water, we might rig such a thing.

I guess the bottom line is that I think the bulb's fine for most places, but it you're planning to stick around mostly in those waters, it's probably not the best choice.

I don't think that the separate rudder's all that bad, since the keel's so much deeper. If a line slides off the keel, the rudder will hopefully go over it fine.

TJ

[coffsguy]

Originally Posted by Jim Cate

While the hazards do exist, this factor was not a big consideration for us. The benefits of fin keel/separate rudder, for us, outweighed the worry about fouling floating debris. We've logged ~135,000 miles since we departed SF years ago, and have only once fouled a crab pot line (in lake Macquarie, NSW) in all that time. Perhaps we've been lucky with that result, but it is our experience. Oh... fouled our own dinghy painter once, long ago and before we switched to a floating line!

Obviously, other folks have a differing reaction to the potential hazard...

Jim

Thanks Jim, I appreciate your comments. Most of my sailing has involved coastal passages and I see it would be less of an problem when you cross oceans.

I've been looking at various hull configurations for my next boat and, while the odd fish trap might be a inconvenience to some, I'd prefer to avoid what happened on recent trip to Lady Musgrave when an unfortunate fellow in another yacht had his motor ripped off it's mounts after the prop became fouled. Bummer!

Cheers

[coffsguy]

Originally Posted by Paul L

You've made a case based on local conditions and then asked the question of folks that are in different conditions - bluewater. In answer to your question, I'd say we had zero consideration. Any boat can get lines, etc tied up in a prop. We've cruised areas where you couldn't travel more that few miles without snagging a long line. These were off Guatemala west coast. They use a small black flag to mark one end of the line and a plastic milk jug to mark the other. These are maybe 50 meters or more apart and basically not visible at night or much in the swell during the day. You pick one up, stop the boat , get your knife out and cut it. Its just part of the game. A good sailing hull with decent performance is also just part of the game.

Thanks for pointing out the difference Paul. So far I've been lucky not to have to go over the side to clear a prop but I know of two instances where one boat was beached and another had a crew member seriously injured when their prop was fouled by fish traps. On one trip off the coast of Queensland several years ago I came across a yacht that had it's motor ripped off its mounts when the prop got fouled by abandoned fishing net.

You comments have helped put the issue in its proper perspective - Cheers

[icemate]

My trip to Australia from Buffalo,NY was with a Bob Perry designed boat built in Tiawan. It came with a modified full keel and a skeg. Had lots of confidence even when sailing with whales as one has to worry about rudder damage. It depends on where you are sailing and sometimes depth is also important. http://www.cruisersforum.com/images/smilies/thumb.gif

[Kim Klaka]

Attached are two documents you might find helpful. The first document is an analysis of the pros and cons of two different types of fin keels - the T-bulb line catcher and the L-bulb which is less likely to catch lines.

The second attachment is a report about craypot entanglements and how they can be minimised. It includes a log of more than 30 entanglement incidents.The report was the first step of an education and awareness campaign here in Western Australia, involving the recreational boating community, the crayfish industry, recreational fishers and government agencies. The campaign appears to have reduced the incidence of entanglements, though I have have no qualitative data to support that view.

I would be very interested to hear from anyone who has tried to detect craypot floats using the latest generation broadband radar (also called “ chirp” or FMCW), and also FLIR infra-red vision systems. We have tried forward-looking sonar without success.

[Stumble]

Other than T bulbs and full keel attached rudders I don't think design really matters that much. And frankly those two designs are so far out on either side of the extreme that I wouldn't own one for cruising for other reasons.

Pot entanglement does happen, and a good set of line cutters on the shaft help a lot. But it is of such a low practical concern I wouldn't stress it. Just keep a sharp knife and a dive mask and fins handy in case.