leaving marina berth - help please

[Dockhead]

Never heard the term, and quick google on it points only to your posts in this thread. But I presume you're talking about the fact that the bows of most boats will blow off more easily than the stern? Causing them to weather-cock around stern into the wind, right?

That's the very effect I would be afraid of since it would spin the bows into the boat to starboard unless you were well clear -- or so I would suppose. Not so?

The port kick is going to impart angular momentum to the boat -- a spinning motion -- which will be reinforced by the "stern boring" effect you're talking about. I fear that this will make it the very devil to keep the boat straight while coming out of the berth if not entirely impossible.

If you can get steering authority within a couple of meters with "full astern" as you suggested, then maybe you could manage it. My boat takes more than a few meters astern to develop steering authority even with full throttle, and a Bav like the OP's with a spade rudder and a saildrive (no prop wash on the rudder) would probably take much more, I would think.

But unless I'm missing something, you would be quite likely to smash into that boat next to you because of the combined and mutually reinforcing effects of port kick and "stern boring". Fin keel boats have little resistance to spinning, which is useful in some situations (I can turn my boat in its own length with bursts astern and ahead; I imagine you can too). In my humble opinion, however, the very bitch in this situation. I don't have much experience in boats with sail drives, however, so maybe you understand something I don't.

 

[Phideaux]

Stern boring is a well understood and used term. /QUOTE]

I must say I've not heard the term, nor can I find a reference to it when Googled and yes, I have done a weekend course with BOSS on close quarter boat handling. I'd love to know more about this technique, please can you explain?

 

[westernman]

The port kick is going to impart angular momentum to the boat -- a spinning motion -- which will be reinforced by the "stern boring" effect you're talking about. I fear that this will make it the very devil to keep the boat straight while coming out of the berth if not entirely impossible.

If you can get steering authority within a couple of meters with "full astern" as you suggested, then maybe you could manage it.

Takes me about 300m going astern at full throttle before I can get anywhere close to controlling direction

But unless I'm missing something, you would be quite likely to smash into that boat next to you because of the combined effect of port kick and "stern boring".

Yep. 100% guaranteed with my boat.

But every boat is different - may be his is light enough and accelerates quickly enough to get out of the berth before he wacks the bows against the neighbour.

However, it is well worth learning how to use warps to control a boat - whatever the size.

By the way, the poor guy at the top of the diagram is kind of stuck.....

 

[KREW2]

I can't work out why anyone would want to struggle to leave the saftey of a marina in 33mph winds.

 

[jimi]

Stern boring is a well understood and used term. /QUOTE]

I must say I've not heard the term, nor can I find a reference to it when Googled and yes, I have done a weekend course with BOSS on close quarter boat handling. I'd love to know more about this technique, please can you explain?

Sten borinis not a technique, it is quite simply the tendency of the stern of a boat to seek the wind. If you did a weekend course on boathandling with BOSS and this was not ecxplained to you , and its importance, then I suggest you are entitled to ask for your money back.

BTW. We are talking AWB with semi balanced rudder and fin keel, which is what the OP was about. We are not talking idiosyncratic longkeelers.

 

[jimi]

The port kick is going to impart angular momentum to the boat -- a spinning motion -- which will be reinforced by the "stern boring" effect you're talking about. I fear that this will make it the very devil to keep the boat straight while coming out of the berth if not entirely impossible.

If you can get steering authority within a couple of meters with "full astern" as you suggested, then maybe you could manage it. My boat takes more than a few meters astern to develop steering authority even with full throttle, and a Bav like the OP's with a spade rudder and a saildrive (no prop wash on the rudder) would probably take much more, I would think.

But unless I'm missing something, you would be quite likely to smash into that boat next to you because of the combined and mutually reinforcing effects of port kick and "stern boring". Fin keel boats have little resistance to spinning, which is useful in some situations (I can turn my boat in its own length with bursts astern and ahead; I imagine you can too). In my humble opinion, however, the very bitch in this situation. I don't have much experience in boats with sail drives, however, so maybe you understand something I don't.

not at all you come out fast with the rudder straight, stern boring starts slowly and finishes quickly. In a confined space you need to get turning as fast as poss, and coming out fast minimises the initial turn so you avoid the neighbouring boat but starts to get it turning before the rudder gets steerage way. then you can turn very fast in total control. Once out in the faiway throttle down to maximise flow over the rudder and maximise control , you use the effect off the wind rather than fight it. If you need to straighten quickly rudder hard over and a burst of max power forward to skoot water sideways off the rudder without imparting forward motion.Trying to get the bow throough will very likely leave you pinned at the end.

A usefule exercise is to rotate the boat in its own length and space using combination of forward and reverse. Try it! (PS keep rudder hard over all the time a;lternating reverse port kick, and forward skoot water off rudder to keep boat turning)

 

[westernman]

A usefule exercise is to rotate the boat in its own length and space using combination of forward and reverse. Try it! (PS keep rudder hard over all the time a;lternating reverse port kick, and forward skoot water off rudder to keep boat turning)

Not possible against the wind in 20 knots in my boat. Not possible in a 40ft AWB in 30knots.

 

[BlueSkyNick]

I havent read the whole thread, but ...

The first thing I would do before getting into this situation again is to go and buy two more warps.

You shouldn't be using one line for two jobs, even though a lot of people do.

OOps sorry, just read that it's a charter boat - check the inventory before you set off, next time.

 

[jimi]

Not possible against the wind in 20 knots in my boat. Not possible in a 40ft AWB in 30knots.

Yeah total rotation gets tricky in high winds, but the tequnique gained whilst practising in lighter winds will be of use in higher winds . And don't forget that in a marina the boat hull is often fairly well sheltered fby neighbouring boats from the full effect of the wind

 

[westernman]

And don't forget that in a marina the boat hull is often fairly well sheltered fby neighbouring boats from the full effect of the wind

Ha Ha.
Last winter I had 163km/hr in my berth.

 

[Dockhead]

not at all you come out fast with the rudder straight, stern boring starts slowly and finishes quickly. In a confined space you need to get turning as fast as poss, and coming out fast minimises the initial turn so you avoid the neighbouring boat but starts to get it turning before the rudder gets steerage way. then you can turn very fast in total control. Once out in the faiway throttle down to maximise flow over the rudder and maximise control , you use the effect off the wind rather than fight it. If you need to straighten quickly rudder hard over and a burst of max power forward to skoot water sideways off the rudder without imparting forward motion.Trying to get the bow throough will very likely leave you pinned at the end.

A usefule exercise is to rotate the boat in its own length and space using combination of forward and reverse. Try it! (PS keep rudder hard over all the time a;lternating reverse port kick, and forward skoot water off rudder to keep boat turning)

OK, if I understand you correctly, you are suggesting that the wind will help you more turning stern into the wind, than bows into the wind, once you are clear of the boat to starboard.

I think most sailors are familiar with the tendency of most boats to weather-cock into the wind stern-first. My boat does this and my previous boat (37 foot, 10 tonne displacement) did too. I have never heard of either "stern boring" or "sten borinis" and Google doesn't know these terms either, but I don't disagree with the effect you are describing.

Certainly, this effect will help you turn stern-first into the wind after you are out of the berth, but I would not have imagined that to be the hard part of the maneuver. Once you are out of the berth you already have way on and you have steering authority. Once you have steering authority, you can turn any way you want to.

Your "sten borinis" effect, though, is working against you when you're in the more difficult part of the maneuver, which is getting out of the berth in the first place. The wind will tend to rotate the boat around its keel bows-toward the boat to starboard, which unfortunately coincides with the angular force exerted by the port kick, so that means pushed around by two different forces you are going to be spun around really hard. Maybe on your boat you can just power through that strong spinning motion. Definitely I could not on mine, so I would need either warps or bow thruster or preferably both, to counteract this spinning motion and avoid expensive and embarrassing consequences. Admittedly on your boat you can get away with more degrees of not being straight. The overall length of my boat is more than 60 feet with davits, and with 16 feet of beam just a couple of degrees out of being straight means crunch.

Once you have way on and are out of the berth, your job is already easier. If you put the helm to port and turn the stern into the wind, the boat will respond in a snappy manner because of the effect you are talking about from the wind. But you don't necessarily want the boat to turn in a snappy manner, given the danger to starboard to your bows. I have been listening carefully but I have still not heard any reason why you would not put the helm to starboard to put the bows into the wind so you can motor out of the marina in ahead. With full steering authority you will easily overcome the tendency of the wind to push you in the other direction. In fact, these forces (wind and rudder) acting against each other will benefit you because it will slow the rate of turn and help you make a wider arch, which will bring you clear of the boat to starboard. In fact the two forces acting against each other will impart a lateral motion away from the obstacle. You said this would be "dangerous" but I still have not heard why you think so. The way you propose turning, the wind will be blowing you into the next boat; if you are turning the other way the wind will be blowing you away from the obstruction. In a weaker boat with a smaller rudder you might stall a little while trying to counteract the wind, but this stalling would carry you away from the obstruction, not into it. I would not shift into ahead without putting the helm back to neutral or port; that's basic close-quarters maneuvering isn't it. Maybe it's a question of how different boats handle the wind.

 

[BlueSkyNick]

Ha Ha.
Last winter I had 163km/hr in my berth.

in which case you wouldn't have wanted to be going out anyway!

 

[Ex-SolentBoy]

Fascinating thread.

Some poor chap asks how to get out of a marina berth and there are 50 different suggestions.

Who said sailing was easy?

 

[Dockhead]

Fascinating thread.

Some poor chap asks how to get out of a marina berth and there are 50 different suggestions.

Who said sailing was easy?

LOL! Sailing may be easy, in fact, but getting out of a marina berth with a wind blowing from your port side, another boat to starboard, and a right handed prop (port kick), is te very bitch! Hence the involved disputation.

 

[Poignard]

Who said sailing was easy?

Dunno - but he was a bloody fool, whoever he was.

 

[Phideaux]

Sten borinis not a technique, it is quite simply the tendency of the stern of a boat to seek the wind. If you did a weekend course on boathandling with BOSS and this was not ecxplained to you , and its importance, then I suggest you are entitled to ask for your money back.

No, just that the term "stern boring" wasn't used, hence my confusion when you stated "well understood and used term".

 

[webcraft]

Stern boring is a well understood and used term.

Is that the same as a$$ reaming?

- W

 

[jimi]

OK, if I understand you correctly, you are suggesting that the wind will help you more turning stern into the wind, than bows into the wind, once you are clear of the boat to starboard.

Certainly, this effect will help you turn stern-first into the wind after you are out of the berth, but I would not have imagined that to be the hard part of the maneuver. Once you are out of the berth you already have way on and you have steering authority. Once you have steering authority, you can turn any way you want to.

Your "sten borinis" effect, though, is working against you when you're in the more difficult part of the maneuver, which is getting out of the berth in the first place. The wind will tend to rotate the boat around its keel bows-toward the boat to starboard, which unfortunately coincides with the angular force exerted by the port kick, so that means pushed around by two different forces you are going to be spun around really hard. Maybe on your boat you can just power through that strong spinning motion. Definitely I could not on mine, so I would need either warps or bow thruster or preferably both, to counteract this spinning motion and avoid expensive and embarrassing consequences. Admittedly on your boat you can get away with more degrees of not being straight. The overall length of my boat is more than 60 feet with davits, and with 16 feet of beam just a couple of degrees out of being straight means crunch.

Once you have way on and are out of the berth, your job is already easier. If you put the helm to port and turn the stern into the wind, the boat will respond in a snappy manner because of the effect you are talking about from the wind. But you don't necessarily want the boat to turn in a snappy manner, given the danger to starboard to your bows. I have been listening carefully but I have still not heard any reason why you would not put the helm to starboard to put the bows into the wind so you can motor out of the marina in ahead. With full steering authority you will easily overcome the tendency of the wind to push you in the other direction. In fact, these forces (wind and rudder) acting against each other will benefit you because it will slow the rate of turn and help you make a wider arch, which will bring you clear of the boat to starboard. In fact the two forces acting against each other will impart a lateral motion away from the obstacle. You said this would be "dangerous" but I still have not heard why you think so. The way you propose turning, the wind will be blowing you into the next boat; if you are turning the other way the wind will be blowing you away from the obstruction. In a weaker boat with a smaller rudder you might stall a little while trying to counteract the wind, but this stalling would carry you away from the obstruction, not into it. I would not shift into ahead without putting the helm back to neutral or port; that's basic close-quarters maneuvering isn't it. Maybe it's a question of how different boats handle the wind.

Jings mate, you're in the friggin constricted space of a marina aisle, not in the middle of the atlantic. If you want to get enough speed up to get your bow through 20 knots of wind in a constricted space then it is dangerous cos you'll hit something or spend 3 days mucking around with warps cos you're fighting the elements not using them to your advantage. I've seen more damage done by namby pamby handling and excessive warping
than by robust use of the throttle!

Oh and if you had read and understood my earlier post I clearly stated that stern boring comes into full play when out the berth, the initial effect is the prop kick, second the rudder flow, third stern bore. Coming out backwards gets them all working harmoniously together

 

[WoodyP]

Its a 20 knt wind, no tide, and a relatively light weight boat, so why all this exitement about crashes and bangs here there and everywhere.

Warps, roving fenders, and a bit of care relating to the boat characteristics. It ain't rocket science. If you do end up resting against your neighbour, it isn't going to sink him, you, or cause damage.

Try it single handed with 4 knots of tide under the boat as well. Then it will become interesting for the spectators.

 

[jimi]

Try it single handed with 4 knots of tide under the boat as well. Then it will become interesting for the spectators.

I was going to describe my single handed technique, but suspect its a bridge too far for this lot ;-)

Suffice it to say it involves a lot more speed and power!!

but sadly no jib up the back stay or kedged out anchor ;-)