Going Down Bay

[Flutterby]

I am planning to go down bay with my yacht club in late September. Last night we were discussing tides. Here is my question:

Should a trip from Bethel Island to say Jack London Square be planned around the tides? Or is it ok to just go when it is convenient? What about through the Carquinez Straits?

What do you do when going down bay???

 

[c]

I'm no expert, but it's always worth checking tides (and more to the point, currents) when making a long trip. My boat cruises at 12.5 kts, and the currents in the bay can reach 4-5 knots pretty regularly (for instance, today and for the next few, there's a maximum ebb tide at the GG Bridge of 5.5 knots. So if I were to go against this current, it would be pretty slow going!

Conversely, "going with the flow" can be really helpful for trip time and fuel consumption.

Late September should be a great time, and currents in the Bay mostly don't exceed 2-3 knots for the week of Sept 17, but get much bigger (5kts) Sept 27-30. They're always greatest at the Gate itself, and smaller as you go away. The currents at the Carquinez Straits are somewhat less, but still worth noting.

Have a great trip!

 

[roy hope]

hi flutters, i like to go as far as benica on the first leg.
it is a good marina and a short walk to town.also by
going to benica you can ride the tide on both days, it helps save the fuel. roy

 

[goplay]

Optimizing around the tides can certainly help with fuel consumption. On a planing boat it is less an issue of speed for making way.

The only thing I am vaguely conscious of is not to be into a strong wind with the tide running in the opposite direction or into the wind with the tide running against you, since both makes for a rougher ride. The rougher the ride, the slower you go not for current but just to reduce the slamming. Generally that means not heading into San Pablo Bay in the afternoon, which may be unavoidable!

Around the Bay, the roughest section is between Alcatraz and SF, because of the wind, generally in the afternoon, inconjunction with the tides and currents.

 

[AbsoLoot]

Liz,

I absolutely think you should take the tides into account. The main reason is that in areas where there is a strong current and an opposing wind the waves will stack up into a steep chop which can be very uncomfortable. The main areas that I worry about are San Pablo Bay and the Suisun Straits. The winds are almost always come from the west or northwest so I always try to time my passage for when the tide is rising. This may make your speed over ground slower than if you were running with the current, but you will be able to travel much faster over the smoother water. I have been fortunate enough to have only had one bad trip across San Pablo Bay and I'd like to keep it that way.

I hope you all have a great trip and I'm looking forward to your report.

 

[Flutterby]

Thanks for everyone's input! My training was to always coordinate departure based on best conditions ie wind and currents. I think that is a prudent thing to do. Not everyone in my yacht club seems to be conversed on these conditions. Maybe we can get them educated!!!!

 

[dugsboat]

FB. I've done that trip in all sorts of boats, and actually have turned back several times even on a 39' Carver. The spray was over the flybridge. Like Dave said, if you get the predominant western wind and an outgoing tide, look out. Everything can be fine as you go past the Carquinez, but suddenly on the other side it gets very rough. I've also done the trip in a 20' Sea Ray but tucked behind, and I mean like in formation, a 39' Sea RAy. Other times it is smooth as glass and no big deal. Go early in the morning before the wind develops or at least time being on the west side of the straits before the wind develops.

 

[Monterey10]

I agree with the above. Going out with the out tide and in with the incoming is ideal. I did 18 mph running against an outgo. As I turned sideways to the current, my speed jumped to 23 mph. As important is to make your trip through
the straights early in the morning before the winds. I like Benicia quite a bit. I would recommend staying there as well. The main street is 1 block from the harbor. There's a good meat market and restaurants up and down the street. I beleive the farmers market is on Thursday.

You want to avoid running down through the San Pablo bay when you have a strong westerly hitting a strong outgoing tide. The wind tends to make the waves stand up.

 

[BayTrawlerGuy]

Most of the important points have been mentioned, especially caution about crossing San Pablo Bay on an outgoing tide but into the wind. I've been out the Gate many times, but the worst seas I've ever encountered were on San Pablo Bay. It was the only time I've ever buried the bow of my 36' trawler in green water--and my bow is normally 7.5 feet above the water.

I'd also add that since the tides flow "up" the Delta (think waves emanating from a bay that is pumped full and empties twice a day) it is possible to ride an advantageous tide all day "up" the Delta, but going towards the Bay, you will "cross" both advantageous and adverse currents.

BTG