Tide/wind/currents

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tfluce

.
Jun 17, 2012
10
Hi,
I'm brand new to NorCal and my reading tells me I should be looking up the Delta for more pleasing weather experiences than we have here in SFO Bay. I'm harbored at Berkeley Marina. My experience in sailing was beginning back in Boston Harbor and down the Atlantic to as far as Block Island, not a cozy little lake, but not like out here as I'm told.
So I went up to Pittsburgh/Collinsville last month on what turned out to be a disaster for my rudder--totally wrecked on a submerged ship in Pt. San Pablo Yacht Harbor which I'll tell about elsewhere. What was totally new to me were the 3 forces that made anchoring a puzzle to me: the tide, the wind, and the currents--the mouth of the Sacramento and San Joaguin Rivers. I found the 3 forces battling each other and keeping me guessing all the time. I would set anchor and find that Molly Brown (my boat, Hunter 1980 33) would turn its rear to the wind instead of into it and eventually I'd have to pull up anchor and try again. I would slip (yeah might be my problem of not providing for the right scope). And once I slipped clear across the channel in front of the two rivers hitting the starboard buoy next to the land on the deep water channel.
So, I need to learn how to deal with these 3 forces. Must I use two anchors?
Thanks! Tom Luce, Molly Brown, HUnter 1980, 33'
 
Jan 22, 2008
1,667
Hunter 34 Alameda CA
Hi Tom,

Welcome to the forum and to the SF Bay. You have already discovered there are some unique conditions around here. My advice is to take it slow and read as much as possible while enjoying your boat.

The Delta is a great place...like the Virgin Islands without the airfare. But as you have experienced, there are some tricky areas. Make sure you have good charts...the Bay and Delta Yachtsman book it the best. It is about 30+ pages of convenient sized charts of the entire bay, ocean and delta areas around here.

My boat sails the same way about the anchor line in certain conditions here. That's what happens in these fin keeled boats. My anchor, 15 feet of chain and 10 feet of rode are still on the bottom over at China Camp/ McNears beach. The boat turned around in the middle of the night and the keel sawed through the anchor line. We drifted around until morning when someone came over and woke us up. There are ways to manage that....look up anchor sentinel, or kettle weight (we had one!). Also search about riding sails. They can keep your boat oriented when you have competeting current and wind conditions. By the way, there are lots of other areas in the bay and Delta where that doesn't happen. An easy place to anchor is Decker Island off the Sacramento River (behind the island).

Sounded like you need more scope for the anchor. Plan on 7 times the distance from the water depth plus the height of the bow from the water. Make sure you have a 15 foot piece of chain on the anchor line as well.

Just go slowly and gain experience. Consider taking some lessons over at Tradewinds in Richmond for some basic bareboat techniques. There will be an instructor with local knowledge that will have very valuable information to help you. Also, consider joining a Yacht Club or Sailing Organization where there are other folks that are knowledgeable in the area who you can travel with and learn. Consider racing. You're not out to win, just to learn. See what others are doing.

Good luck and enjoy your boat.

Allan
 
Feb 26, 2004
23,063
Catalina 34 224 Maple Bay, BC, Canada
Buy Kimball Livingston's book, Sailing The Bay. Answers all your questions. Great read, too.

For anchoring in opposed wind & current (from a C36 Forum discussion I had)

Anchoring lesson learned I had another experience that I thought others might benefit from.

A couple of weekends ago, we anchored off of China Camp in the North Bay of SF Bay. Anybody who's been in this area will know that the current really rips through here. We had motored to the beach at the time that the tide changed, so we weren't on the boat when it swung. Somehow it got caught up against the rode, so that when we got back on the boat the rode was running from the bow down the (port) side of the boat to the stern.

I tried to pull it free but the current was too strong. I tried to pull the stern of the boat around with my dinghy but couldn't do that as I only have a 2hp outboard. I was afraid to motor around as I didn't know how close the line passed to the prop. I tried sailing off, but that didn't work either.

I figured that we could just leave it as is and wait until the tide shifted again. So I stretched out in the hammock I'd stretched out from the mast to the forestay. Nice and relaxing, bouncing on the waves.

After a half hour, though, I suddenly noticed that the movement of the hammock had suddenly changed. On sitting up I saw that we were dragging anchor. I tried releasing the anchor rode, but I couldn't.

On we drifted, down towards the other boats. It was a really helpless feeling as we passed one boat after another. Then a guy in a dinghy with a larger outboard came up and offered help. We tied a line from our stern to his dinghy and he was able to pull our stern around to the point where we could drift free of the line and I started up our motor, pulled our anchor and re set it.

My two biggest mistakes: (1) I should have thought of running my spare anchor out and trying to kedge us around and even if I hadn't been able to, at least I'd have had a second anchor; (2) I should have tied a buouy to my line and had a knife ready to cut the rode in case we started dragging anchor.

Anyway, lessons learned. Maybe this experience will help somebody else in a similar fix.
__________________
SF Bay
1998 C36
#2
07-21-2011, 06:54 PM
stu jackson c34

Captain
Join Date: Dec 2008
Posts: 771



John, glad you're safe. Good lesson learned. I always use a sentinel when I anchor up there. The sentinel is NOT used to keep the anchor down, but rather to keep the rode down when the boat swings. Unless it's blowing like stink when the wind shifts, it works. I've had keel wraps up there myself, before I started using the sentinel, although I've always had lots of rode out since there's so much room. I guess I was fortunate enough not to have dragged, but the motion really s*cks. Our sentinel is an 8# mushroom anchor on its own separate rode, connected with a carabiner. Most folks recommend the heftier 15# model, but ours has worked for the past 13 years.

[added] The trick with the sentinel is that when the current reverses there is usually (I say usually) little pull on the rode, so the sentinel drops the rode below the keel as the boat swings (unless it's blowing like stink when the current reverses).
__________________
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Last edited by stu jackson c34 : 07-22-2011 at 01:54 PM.


#3
07-21-2011, 10:27 PM
plaineolde

Captain
Join Date: Nov 2008
Location: Turnersville, NJ
Posts: 412



I use the identical setup that Stu has. A nearby anchorage, Fairlee Creek, has a strong incoming/outgoing tide through the 30 foot wide entrance and it creates strong eddy currents. The sentinel prevents keel wraps quite well, have never had one since I started using it.
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Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay


#4
07-22-2011, 02:07 PM
John Reimann

Captain
Join Date: Dec 2008
Location: Oakland, CA
Posts: 312


Another lesson
Okay, so now I've learned another lesson. I take it the sentinel attached through a carabiner can slide up and down the rode?
__________________
SF Bay
1998 C36


#5
07-22-2011, 02:35 PM
stu jackson c34

Captain
Join Date: Dec 2008
Posts: 771



Yes. Anchor normally. Attach carabiner to the shackle at the top of the sentinel and another rode to the sentinel shackle, keeping the carbiner free to move. Clip the carabiner to the main anchor rode. Drop the sentinel with its own separate rode and slide it down the anchor rode, about the depth of the water, not much more (figure high water, it'll either sit in the mud at low water - good with a mushroom sentinel anyway, or keep the rode down at higher water). Tie off the sentinel rode to one of your bow cleats. I do it off the port side, don't use the second anchor roller for the sentinel. I keep the sentinel, it's shackle, the carabiner and its own rode in the port locker. The rode is only about twenty to twenty five feet long, 3/8" 3 strand. Our anchor rode is 1/2". The carabiner is there to have a big enough opening to slide down the anchor rode, a shackle itself is too small. Makes it much easier to set and retrieve also.
__________________
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Last edited by stu jackson c34 : 08-15-2011 at 01:59 PM.


#6
07-25-2011, 07:36 AM
John Reimann

Captain
Join Date: Dec 2008
Location: Oakland, CA
Posts: 312


?
I'm not sure I understand what you're saying. Are you saying this:

You leave out about the amount of rode on the sentinel as the water depth at high tide. You clip the caribiner to the end of the anchor and around the rode of the main anchor line. In other words, the end of the sentinel is right along the end of the main anchor line and allowed to, in effect, slide up and down that rode by virtue of the fact that the carebiner is around the anchor line.)

As I'm visualizing it, this will in effect keep the anchor rode going more vertically straight down to the bottom and then horizontal along the bottom.
__________________
SF Bay
1998 C36


#7
07-25-2011, 05:04 PM
stu jackson c34

Captain
Join Date: Dec 2008
Posts: 771



Exactly, you got it. When there's no wind, what you said will happen. When the wind picks up, the sentinel will rise, but (hopefully, and based on my experiences at China Camp) when the currents reverse, the sentinel will drop down again and keep your rode from fouling your keel.
__________________
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)


#8
01-08-2012, 11:34 PM
bakerha

Petty Officer
Join Date: Jul 2010
Posts: 88


Does the sentinel control anchor swing?
Stu: Just read somewhere, while investigating anchor riding sails, that also is a technique to control swing at anchor. Seems like it would help the main anchor stay put and help with bow rise and fall as well?
__________________
_____________
Harold Baker
S/V Lucky Duck
Sandusky Ohio, Great Lakes
1989 C-36 mkI TR/WK M25XP


#9
01-14-2012, 04:18 PM
stu jackson c34

Captain
Join Date: Dec 2008
Posts: 771



Harold, it should work a bit when there's no wind, but when it pipes up? No, it won't help since the rode is pretty much all stretched out by then.

Like everything else with close-quarter anchoring, there simply is no magic bullet.
__________________
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
 

tfluce

.
Jun 17, 2012
10
He Stu, what a great return message and so chock full of good info. I will treasure this. Thanks!
 

tfluce

.
Jun 17, 2012
10
Thanks!

Wow you sailboatOwners.com folks are fantastic! Thanks. I've got a lot of learning to do.



Hi Tom,

Welcome to the forum and to the SF Bay. You have already discovered there are some unique conditions around here. My advice is to take it slow and read as much as possible while enjoying your boat.

The Delta is a great place...like the Virgin Islands without the airfare. But as you have experienced, there are some tricky areas. Make sure you have good charts...the Bay and Delta Yachtsman book it the best. It is about 30+ pages of convenient sized charts of the entire bay, ocean and delta areas around here.

My boat sails the same way about the anchor line in certain conditions here. That's what happens in these fin keeled boats. My anchor, 15 feet of chain and 10 feet of rode are still on the bottom over at China Camp/ McNears beach. The boat turned around in the middle of the night and the keel sawed through the anchor line. We drifted around until morning when someone came over and woke us up. There are ways to manage that....look up anchor sentinel, or kettle weight (we had one!). Also search about riding sails. They can keep your boat oriented when you have competeting current and wind conditions. By the way, there are lots of other areas in the bay and Delta where that doesn't happen. An easy place to anchor is Decker Island off the Sacramento River (behind the island).

Sounded like you need more scope for the anchor. Plan on 7 times the distance from the water depth plus the height of the bow from the water. Make sure you have a 15 foot piece of chain on the anchor line as well.

Just go slowly and gain experience. Consider taking some lessons over at Tradewinds in Richmond for some basic bareboat techniques. There will be an instructor with local knowledge that will have very valuable information to help you. Also, consider joining a Yacht Club or Sailing Organization where there are other folks that are knowledgeable in the area who you can travel with and learn. Consider racing. You're not out to win, just to learn. See what others are doing.

Good luck and enjoy your boat.

Allan
 
Jan 22, 2008
128
Hunter 27_75-84 Wilmington, NC
Re: Thanks!

Hey this is really great info. Next month an article I wrote will appear in Sail Magizine. It describes a bad experience I had with competing wind/current here in NC. Really like the mushroom anchor idea - do you think it would help reduce swing in high wind if the mushroom were dropped off the stern? Tony
 
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