Boat whips

[kokko]

This past season I experimented with a home made boat whip. If you look online they are hellishly expensive. I made a prototype with 1/2" schedule 40 inside 3/4" schedule 40 and connected to the dock with a flagpole bracket. The length was 4'. I mounted on the dock amidships so the far end was aft the cuddy and under the boom. I had a line from the end of the whip that I secured to the midship cleat.
If the boat moved toward the dock the whip flexed and moved it out again.
I intend to add a 1/4" diameter section of fiberglass rod to increase the stiffness and have at least two, maybe three whips.

[jdoorly]

I purchased 5' x 1/4" fiberglass rods in Truevalue hardware as bicycle flags for like $5.

[hectoretc]

I've searched this site and not found any other references to boat whips, an Internet search brings up a couple products providing comments as Kent made to keeping your boat from hitting the dock, but even after reading Kent's post, I don't think I understand how it does whatever it does...

[GreenLake]

I picture them as bent rods that are fixed to the dock and push the boat away from the dock, like springs. I've not used any, so I don't know whether you tie the ends to some clamps or whether they push against the hull.

I imagine the effect would be similar to having pilings on the side opposite the dock - they provide a means to tie up the boat without it touching the dock and without having fenders in contact.

[kokko]

http://www.mooringproducts.com/index.htm

[hectoretc]

Thanks Kent

Interesting... these must be for personal mooring locations only, as in the picture and per your reference they appear to be bolted to the docking surface?

On the one hand, I'm really suprised that they would not snap. That's quite a bend of the "whip" in the photos. On the other hand, you commented your whip length was 4 feet of 1/2 inside of 3/4" so I'm thinking that is a pretty solid piece. Not being an expert but having used a fair amount PVC pipe, I'm suprised you'd see much flex at all in that short of a piece.

Is there any "specs" or guess-t-mates for the amount of mass or wind speed/surface area for a particular size (diameter), length etc? This would definitely reduce the need for fenders and those kinds of things on my dock.

Very interesting - Thanks! - Scott

[kokko]

If you look at the websites that sell boat whip, they seem to handle a lot of weight. I ran a test case with one whip at the midpoint of Truelove. It did not keep the boat off the dock if wind/waves were pushing it to the dock.
If I added a second or third whip I may not need fenders, but I will not take that chance.
I do think the added stiffness I'd 1/4" fiberglass rod will help a lot. I don't know how much I can trust schedule 40 under constant flex