Docking and Leaving the Dock on a Catamaran

[Talbot]

Originally Posted by yeloya

You can easily identify someone coming form mono culture whgen docking with a cat; he would try monouevre with the rudder... With the cat you should forget the rudder and put yr hands on two throttles. Second thing, unlike the mono where you need a certain speed to control the boat, in the cat you have to keep the speed minimum and act slowly.

When you are new to driving a cat, I would totally agree with you.

However, use of rudders and balancing the engine thrust can add a significant dimension to your manoeuvring. You can actually make the boat go sideways.

As for the speed part. On my catalac, when the wind was blowing the only thing that kept the boat from loosing steerage was by use of some speed - single engine and twin rudders are not for the faint hearted.

[mark_morwood]

I also agree on starting with just engines, but adding the rudder gives you even more options if the rudders are behind the props.

As an example to move the boat slowly sideways to stbd:
- forward on port engine (slow)
- reverse on stbd engine (enough to cancel fwd movement from port engine)
- helm hard to port (cancels spin induced by opposite engines)
Results in the boat moving slowly sideways to stbd.because of the wash coming off the port rudder.

You can also add in the effect of prop walk, but I usually struggle to keep that all straight in my head.

Mark.

[amytom]

It all depends on where the engines are in relation to the rudders. My PDQ has the engines midships so I can sit and pivot almost within my boat length. Add the rudders to give sidways motion and I can walk right into the slip... somedays. Sometimes I still come in and make a fool of myself. Practice, practice, practice.

[Tom and Maje]

Originally Posted by Hank&Karen

NauticEd has a great catamaran maneuvering game online called Cat NED:

Learn to sail with NauticEds Online Sailing Games

You maneuver your cat through a crowded marina, backing into various stations to get fuel, ice, etc. It is designed to help understand the "two throttle, no rudder" technique for cats. I think it's a great tool for learning. The fun race for faster times in this game does not, however, promote following the best advice I've received from my instructor:

"SLOW IS PRO"

I see that you had Mike as well.

Maje

[Cotemar]

Two throttles, no rudder and a spring line (Mid ship)
Works well for us.
Keep in mind a lot of Fountaine Pajot and Lagoons have the props behind the rudder, so throwing water at the rudder does not work.
My rule is "only go as fast as you want to hit the dock"

[Talbot]

Originally Posted by Cotemar

Two throttles, no rudder and a spring line (Mid ship) Works well for us. Keep in mind a lot of Fountaine Pajot and Lagoons have to props behind the rudder, so throwing water at the rudder does not work.
My rule is "only go as fast as you want to hit the dock"

Berthing using throttles alone is the most simple method of control. (Which is why it is the one taught by the schools and also used by mobos). However, with the obvious exception of those cats with the screws behind the rudders, the use of rudders in conjunction with the engines can allow some very advanced manoeuvring., and even make the boat go sidewats.

The only way to learn is to find a day without wind, and a time without tide, and give it a try at very slow speeds to see what happens.

[JustHank]

Hi Maje - actually had Captain Norman Martin, but I bet "slow is pro" is common wisdom amongst experienced sailing instructors...

Sitting in Soper's Hole after a great downwind sail down the north side of Tortola today...Happy New Year!

[DotDun]

Remember, a cat doesn't pivot at the stern, the pivot point is midship - right at the middle of the keel. Hence in tight slip, spring lines are your friend.

My slip is 25.5' with a 23' beam, we back in pivoting on a piling, and leave by pivoting off a spring line to an aft cleat. We have to turn 180 around a 4' wide finger dock when leaving.

[tsmwebb]

Originally Posted by Tallbot

Berthing using throttles alone is the most simple method of control. (Which is why it is the one taught by the schools and also used by mobos). However, with the obvious exception of those cats with the screws behind the rudders, the use of rudders in conjunction with the engines can allow some very advanced manoeuvring., and even make the boat go sideways.

The only way to learn is to find a day without wind, and a time without tide, and give it a try at very slow speeds to see what happens.

Spring lines are great though not cat specific. I generally maneuver into the dock with just the throttles and go for a spring. I have experimented with thrust vectoring using the rudders and it works... But the lateral effect is weak on my boat and easily overcome by a modest wind or tide (I've got 2gm20's with two bladed folders). In the calm conditions where it works it isn't usually needed. I typically leave it out for simplicity's sake. However, on my boat the rudders have a very noticeable effect on the rate of turn even when twisting on one spot. I often use the rudders when I want to spin quickly (eg. making a 180 in a fairway with a bit of wind or current). While slow is great when you can do it, if you have a tight fit and a cross current or wind there is a limited amount of time you can take. Waving a landing off and going around again is often the best choice but a some point it may no longer be an option...

Tom.