posted 05-24-2003 10:03 PM ET (US)            

I used to manage a marine store in Hyannis. One of the Kennedys used to tow a RIB behind his sportfisherman. One day he came in with a twisted bow eye, demanding that we replace his RIB because it had been lost at sea. The bow eye still had the eyebolt on it. In other words, id didn't break, it was pulled through the fiberglass.

posted 05-29-2003 07:21 PM ET (US)            

Ditto the concern about the line parting. This is my plan:

I am going to use 3 strand ¾” Polydacron. It has a tensile strength of 9500 lb. and low stretch. Using 10% of tensile as a safe working load gives me 950 lb of pulling, with little stretch. 950 lb is below the safe working load in the manufactures specification. Further, I believe that less than 500 lb will be enough. If there is going to be a problem, I do not want it to be the line parting.

Low stretch is good in towing. Nylon can store energy and give you some bungee cord effects which are undesirable for a tow. A little stretch is good for shock. A lot is bad. The above concern about what happens if the line parts is another reason to have low stretch line.

I have watched the Coast Guard towing over the years. They always place the vessel in tow waaay back. I plan to have 200’ of line available. This is to prevent the Whaler from running me over in a following sea. I believe 50’ of ¾” line dragging in a sea to be plenty to turn the Whaler away if I am too aggressive with the speed [in a following sea.] Try to hold a 50’ loop of ¾” line at 15 knots to see why. This should happen at least 100’ away from my boat.

With respect to the bow eye strength, here is a copy of my email with BW on the subject:

Me:
“I would like to know if the bow 'eye' is strong enough for towing my 18'
1987 outrage at about 15 knots. This would be the maximum speed in calm
waters. The speed would be 8 knots in moderate seas.”

BW:
”I'd disassemble the bow eye to make sure it isn't rotted/corroded below the surface and make sure a safety line is attached, just in case.”
Me:
“Good advise, thanks. Can I use the Samson post on the bow for the safety
line?”

BW:
“The sampson post is attached to an aluminum plate that is molded into the
hull (under the fiberglass). That would probably be the best tie off
(safety) point, although some people will go to the extreme measure of
criss-crossing two tow lines through the bow eye, run them along the
outside of the boat (under the gun'l lip) and then tie the lines off at the
stern eyes.”

Sounds like good advice to me. My family towed an 17' whaler at 8 knots behind a troller for years with success. The second technique recommended by BW is essentially what my father used towing the 17’ whaler.

The practice tow was a success. Things go easier with the whaler up on a plane, or down around 8 knots. There is of coarse more pull just before the whaler planes. The Whaler tracks very will up on a plane. She tends to roam around a small bit going slower, but not enough to cause a problem. Ride the Whaler just behind one of the water humps left by the towing vessel, almost in the trough. Riding on a down hill spot will cause the tow to surf too much. Riding all the way on the up hill spot causes too much drag.

doobee: running in tandem is always fun as well.

posted 05-29-2003 11:10 PM ET (US)            

Regarding stretch: low stretch is better but it can still snap back at you when it parts. I saw a video on TV of some kids towing an empty tube at high speed. The tube was flying up in the air like a kite. Suddenly the tube took a nose dive and when it hit the water, the towline parted, flew into the boat, and killed the video camera. I wonder if the cameraman knows how close he came to getting killed. Ski tow lines are generally very low stretch. If a 10lb inflatable tube could snap a towine with 1200lb tensile strength, imagine what could happen if your 2000lb 18 hits a wake at planing speed.

I think the bow eye is the optimal towing position as far as standard equipment goes. If you attach a safety line from the bollard to the bow eye and to the eye splice of the towline, it would back you up in the event of a bow eye failure, and keep the line from snapping back. There is a potential flaw in this plan, however. The transition from the relativey low bow eye to the relatively high bollard could drive the bow down, causing the Whaler to yaw unexpectedly.

I'm not sure what I think of attaching to the stern eyes and crossing through the bow eye. For starters, the line would put a lot of force on the corners of the transom, leading to chafing of the line and gelcoat. Pulling from the side could bend the stern eyes as they are not intended to be pulled from that direction. While the possibility of a bow eye failure is less, the results would be disastrous should one occur.(remember that scene in JAWS?)

The few boats that I have seen rigged for towing used a bridle system that attached to the hull at 3 or 4 reinforced points in the hull. This would probably be the ideal set up for high speed towing.

posted 05-30-2003 10:59 AM ET (US)            

I'm not sure I buy the tub analogy. A tub flying through the air and auguring in can present a huge amount of force. To me at least, this is very unlike a Whaler planing. At least in any kind of sea for which I would consider the higher speed.

My understanding is that the Coast Guard and professional tow companies have good reasons for their towing speed. It was not always this way. Lots of cleats were ripped off, displacement hulls towed under, boats capsized, etc. before they arrived at this prudent speed. A 5 knot tow will work under almost any circumstances.

And at the end of the day, there is nothing wrong with trolling.

jaccoserv
I’ll call the folks at Lauderdale Marine a call.

posted 06-01-2003 10:17 AM ET (US)            

Sue Lodel, Parts Dept. Mgr.
Twin Cities Marine, Inc.
1600 12th Street
PO Box 126
Two Rivers, WI 54241-0126
Ph-920-793-2715
http://www.twincitiesmarine.com
mailto:twincitiesmarine@lakefield.net

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posted 06-09-2003 07:03 PM ET (US)            

For all that helped:

Spliced up my rig and tried it this weekend. Works like a champ at speeds up to 20 knots in slight chop and swell. The key is keeping the Whaler at the right distance back.

If anybody is interested, I have some pictures of the rig.

posted 06-10-2003 08:22 AM ET (US)            

I had reason on a trip up to our camp in the North Channel of Lake Huron in late May to tow my Outrage 22 behind a larger boat. In my typical "fools rush in" approach, I tied off a 1/2" nylon 3-strand twisted anchor line to the bow eye on the OR22, ran out about 75 feet and tied off to a "Y" yoke coming from the stern tow eyes about 8" apart on the towing boat; the yoke came together about 15' behind the tow boat. We had about 8 miles to run each way, one direction relatively smooth, the other direction 2' to 3' nasty chop; got her up on plane and towed at about 20 MPH for 5 or 6 of the 8 miles each way with no problem (bow eye is still there, but we used a lot of gas!).

Having read this thread, I would probably go to 5/8" line with less stretch next time, and rig up either a 3-point bridle on the towed boat, or at least a second safety connection.

posted 06-10-2003 07:09 PM ET (US)            

Another detail:
The stern eyes are taking a fixed amount of force in my rig. I made their length just shorter than they would be with no load, I then sreched the entire rig between two docks to find out just how much force it took before the bow eye line starts to pull. I did this several times untill I got the pre stress force I wanted. This works well because the bow eye line is much shorter, and thicker th an the stern lines. My goal is 5 to 8 knots of speed when the bow eye starts to pull. I may go higher as I get more miles under my belt.