Spring Line Advice

[Eigenvector]

Seeking advice on how others would have used a spring line for this situation. See picture. Dock cleats shown.



The sketch is pretty much to scale as far and available fairway. 22 kts wind from south, catamaran with windage, 2x 18 hp perkins (not a power house).


Unusually windy day. Luckily the North Sea Wall is a dock/road. Ended up over there (with fenders deployed). It happened really fast.


Spring lined off of there, into the wind, and went sailing the rest of the day.



I had to quote Pee Wee Herman upon my return

https://www.youtube.com/watch?v=9hNIX7V21pU

[Lake-Effect]

What is the usual or prevailing wind at your dock? If it's usually from the south, I would turn the boat around before docking so that it's always pointing S at dock, which would make it easier leaving in a S wind (or any wind, actually).

Otherwise, to leave from a north-pointing dock position in a S wind, I would first move the boat N a bit to the next cleat, then try a spring line from the dock to the port rear corner (~45 degree angle), the idea being it would help turn you as you use mostly the starboard engine, and then drop the spring when the boat is pointing SW and power into the wind.The danger would be banging the starboard rear against the dock if the powered turn doesn't happen fast enough.

(This is all a guess as I have not had to dock or manoevre a big cat.)

[Dave_S]

Hard to say without being there but I would consider attaching the bow to the middle dock cleat then poking my bum out and use the wind to help rotate you. I would be concerned that 22kn could put a lot of pressure on the starboard bow so I would start with a touch of forward on the port engine (if it didn't go by itself) and then in click into reverse enough to slow the rotation then have both engines in reverse from about 30 degrees enough to balance the winds load on the bow but still allow it to rotate. If you have enough hands on deck a safety line from the port bow to the north most cleat might be nice as a back up plan.

The pub might be plan A.

[Dave_S]

Originally Posted by Lake-Effect

What is the usual or prevailing wind at your dock? If it's usually from the south, I would turn the boat around before docking so that it's always pointing S at dock, which would make it easier leaving in a S wind (or any wind, actually).

Otherwise, to leave from a north-pointing dock position in a S wind, I would first move the boat N a bit to the next cleat, then try a spring line from the dock to the port rear corner (~45 degree angle), the idea being it would help turn you as you use mostly the starboard engine, and then drop the spring when the boat is pointing SW and power into the wind.The danger would be banging the starboard rear against the dock if the powered turn doesn't happen fast enough.

(This is all a guess as I have not had to dock or manoevre a big cat.)

A variation to this could be let the boat drift N until the boat is clear of the dock while you have the port stern line on then the boat will rotate itself and you can drive forward on the arc.

[Tillsbury]

Yes, either port stern line (slack) and push yourself off from the dock then do a 180 into the wind while still attached to the dock.

Or, my first thought and what I’d probably do is bow spring to aft cleat on the dock, with a big fender on the bow, and let her drift forwards while rotating clockwise. Then both engines gently astern to crab across into the channel, and reverse upwind past the other boat until the exit is easy.

[GeneM]

I would use a turning line if you could get someone to tend it on shore or go back to retrieve your crew after turning.

A turning line is put on the outboard stern with a faily long lead. Let go all lines except that one. Motor ahead with left rudder, adjusting to keep off the pier. The tight turning line gives you a pivot point and prevents down-wind set. When the bow is into the wind, take the line in.

If necessary, you can now retrieve the line handler and use the wind to spring off the pier to get going.

I'm not sure if your hull sail area will overpower the engine-rudder, if so, do what sailors often do - wait for better weather.

[psk125]

As others have said, turning the boat around (however you think might work) before leaving the dock is the way to go. There is no way you can turn your boat around in the fairway with that much wind. Maneuvering to tie up facing out when you come in from sailing might be easier than changing directions afterwards. You can put the bows in to the dock and swing the port side to. Then, even if the wind changes direction, you'll be pointed out, the way you will always want to go.

[Snore]

Simple, run a line from your starboard now clear to the dock clear aft of the beam.

Your crewman is on the bow with the biggest fender(s) aboard. Forward port engine and the boat will tension the spring line and “roll” on the starboard bow- hence the fenders. When you achieve about a 45 degree angle-
Port engine neutral and starboard astern. Also collect the spring line. Now spin the boat using mostly the starboard engine astern.

If no one is on the dock, loop the spring line back. Just be sure it has a smooth end - no back splice! And it should come easy.

[JC Reefer]

Originally Posted by Dave_S

A variation to this could be let the boat drift N until the boat is clear of the dock while you have the port stern line on then the boat will rotate itself and you can drive forward on the arc.

Meh... not sure I like this so much. Port stern line puts a long line near the business end and I also don’t know about the turning idea. Maybe just my own opinion on it though. Sorry Dave.

The others seem good. Just whip the bow into the wind. Use a turning line if in doubt.

[Dave_S]

Originally Posted by JC Reefer

Meh... not sure I like this so much. Port stern line puts a long line near the business end and I also don’t know about the turning idea. Maybe just my own opinion on it though. Sorry Dave.

The others seem good. Just whip the bow (Stern the boat is backwards) into the wind. Use a turning line if in doubt.

With one person tending the one line and a helmsman, my thinking is.

If you attach a port stern line and allow the wind to push the boat clear the dock, once passed the dock and the wind takes control you wont hit anything and the boat will automatically rotate 45degrees in the right direction. Then you can power forwards into the wind to get out while still attached. I'd do it this way.

If you attach to the starboard bow, my first thought post #3, and end up passed the dock the boat will be facing the dock 45deg the wrong way and you will have no option but to reverse spin without moving forwards going with the wind towards the north dock. You will have to release the line before doing this and hope you can get the boat making ground against the wind before you impact the north dock. It is risky but probably workable on many boats, probably not on mine and 18hp on the OP's boat is marginal in 22kn, which you know will be 28 as soon as you let the line go.

[Dave_S]

Originally Posted by JC Reefer

Meh... not sure I like this so much. Port stern line puts a long line near the business end and I also don’t know about the turning idea. Maybe just my own opinion on it though. Sorry Dave.

The others seem good. Just whip the bow into the wind. Use a turning line if in doubt.

When you say a turning line, do you mean something like a line from the port bow as a backup ? I wondered about this, it could do most of the work for you. You might need a good extra hand to keep the slack out as the stern swung around and secure it at the right time.