Catamaran - Mooring ball banging on hulls

[Rustytony]

Hi, mostly a land lubber but have a small powerboat and owned a 23ft yacht for a few years a long time ago.

I went on a bareboat charter on a new Leopard40 and at one point moored on a ball in a changeable windy harbour.

I couldn’t get the mooring ball to stay ahead.

The sound is sleep depriving and it can’t be good for the gelcoat. No damage was done though. I even had the ball pulled under one hull just ahead of the keel.

The bridle on the bow didn’t help because the wind would blow, push the boat back and tension the line, then in the lull the boat surged forward over the ball.

There was no spare anchor or drogue that I could find. No room for a stern anchor at that mooring anyway.

Does anyone have any tips to avoid this? I thought about a short line drogue off the stern and perhaps an alternative bridle but am wondering if other folk have that issue too?

Thanks for any thoughts.

[Dsanduril]

We're tied up in those conditions now. We use a bridle, the line from each side is just short enough to keep the buoy off the other hull. That does allow it to drift under the boat, on our boat there's plenty of clearance for just about any size mooring ball. If the boat doesn't have the clearance (solid foredeck, low bridgedeck, nacelle) you can tie the ball up even shorter, basically keep it centered under the crossbeam.

If the mooring has a rope pennant that is longer than you would make a bridle you sometimes have to get a little creative with your attachments.

[Richard Harper]

It depends on how the mooring is rigged, if it has a long pendant or if you attach closely to the mooring ball.

I usually have that problem when there is no wind.
I attached a light line to the mooring ball, through a block on the bowsprit and attached it to a length of shock cord and tensioned it with the spinnaker halyard.

But usually I just shorten the mooring lines so the ball can not touch one of the hulls.

[nhschneider]

It’s not often that our monohull is tied to a mooring but on several occasions we’ve had the buoy banging against our boat’s hull. Fortunately, my wife and I can rarely hear it from the aft cabin but anyone forward of the saloon will be driven nuts. Depending on how the buoy is rigged, sometimes we’ll pull it up on deck. If we can’t do that, we’ll go somewhere else.

Fair winds and calm seas.

[Rustytony]

Thanks for those replies. All good info and suggestions.

I can remember some concern in my mind about shortening the bridle because of uncertainty about the cleats.

The ones on the aluminium crossbeam are not suitable for loads so I would’ve had the jury rigged line up over that crossbeam and onto a forward hull cleat.

I was concerned that might place unpleasant loads on that crossbeam at angles it’s not designed to be loaded.

There was no fair lead on the hulls to bring the lines in safely... all anchoring and mooring was set to run off the bridle attached to strong eyes low on front of hulls.

Since it was nighttime I wasn’t keen on messing around under the tramp to try to redo some bridle setups with fittings I hadn’t as yet located (if there even were any).

It’s a problem with chartering... it’s not your boat and if it’s setup isn’t suitable it’s perhaps not wise/allowed/possible to change.

I asked this question for next time, if any, and also I was wondering if I was just doing it wrong and if others had experienced the problem.

Thanks to you all for being so generous with your knowledge.

[SailFastTri]

I use a shock cord attached to the mooring from the bow sprit. It isn’t stretched out unless the boat tries to override the mooring, which can only happen in light winds and opposing current. Then the shock cord prevents the overriding until the boat can turn into the prevailing wind or currents. The breaking strength of the shock cord is probably about 40-50 pounds, but that’s enough strength To hold in the conditions under which this can happen. In strong winds the boat turns and the bridle takes the load.

[Bean Counter]

If the ball has a long pendant, use the pendant and cleat to the bow, short so that the ball can not touch the other hull. Pass a line from the other bow through the top of the ball shackle back to the boat and cleat it short. When you release pull the line through and then un-cleat the pendant. With a short pendant or no pendant use a mooring line through the pendant eye/ shackle to adjust length. If you can not reach the top of the ball or lift it out of the water to attach the second line swim or use the dinghy, or one of those Hook and Moor devices. Welcome to Hook & Moor

[contrail]

My cat has a secondary bow roller about two feet off center line on the crossbeam. In the situation you describe, I do not use a bridle, but simply run a single line over that roller. Then, I pull the ball to that roller, sufficiently that it can't bang either hull or go under the bridge deck.

[DocBrauer]

Put a tire inner tube over it.

[Paul Howard]

At our multihull sailing club our boats are kept on moorings. To prevent the banging, we attach floats to our mooring bridles, pool noodles are most popular, split and then held on with cable ties, to support/float the mooring lines along about two-thirds their length. the lack of drooping line in the water helps keep the boat away from the mooring ball in calm conditions, also keeps the mooring lines from going under the hulls.

[Jackz]

I did this once and it worked....turn the wheel completely to one side and lock it down. run a long line from the cleats on each side through the mooring pennant. this way when you run up on the ball, you will turn before you run over the ball, then settle back.

[Palarran]

Originally Posted by contrail

My cat has a secondary bow roller about two feet off center line on the crossbeam. In the situation you describe, I do not use a bridle, but simply run a single line over that roller. Then, I pull the ball to that roller, sufficiently that it can't bang either hull or go under the bridge deck.

This is exactly what we do.

Originally Posted by DocBrauer

Put a tire inner tube over it.

Did you read the OP?

[doublewide]

This happens when the mooring ball has a long pennant, then you pass your lines through the eye of the pennant and back to your cleats. No problem as long as you are wind rode for in that case the long pennant keeps the ball way upwind of your hulls. Then in the night you discover that you have become tide rode and the ball is now way back between your hulls, making a terrible banging noise. The solution is to eliminate the excessive pennant length. Attach your mooring lines as close to the ball as possible. The way you choose to make them fast to the ball will depend upon the particular ball. You want to restrain the ball tightly, midway between your hulls.