Useful Apps?

[NATBF]

Hello-

Yesterday looked like a good day to explore past Pt. Bonita, so I did, armed with a raft of advice from these and other forums which was extremely helpful. However, the NOAA forecast was for a max 1.4 Kt ebb at 1236 (on 3/31/23), and it was (per my GPS/knotmeter) still around 3 kts ebb at 1600, confirmed later by the NOAA Nowcast. In addition, I became acquainted with what I had heard, and all of you probably know, which is that the current was doing a lot of fairly different things out there depending on just where I was in the channel.

I sure wished I had an app to make better choices... and I bet there are favorites here. Beyond that, I bet there may be some others (like the Sailflow wind app, and maybe the Navionics app or some AIS thing?) that are especially useful.

--> Any app suggestions/commentary would be appreciated. What do you use (and like, or perhaps hate)?

Older threads refer, e.g. to Dial-a-buoy, which sounds great but may now be app-based, and anyway sailflow (and I suspect a current app) would be new-ish. A current set of suggested apps would be appreciated.
* PS: I realize that if they are not free, one cannot use such apps when racing... but for those of us still learning the local environment, much of that sailing is not under racing conditions. It would be nice not to find oneself in a much stronger ebb than predicted...

PS: The current resources I used:
https://tidesandcurrents.noaa.gov/noaacurrents/Predictions?id=SFB1203_18
https://tidesandcurrents.noaa.gov/o...=sfb&subdomain=en&model_type=currents_nowcast

 

[AntsUiga]

My suggestion based on sailing the SFBay since the early 80’s is to forget about apps and learn to interpret the information you see on the water and what you read from your instruments.

There are lots of good presentations from experienced sailors that will provide a knowledge base that will always exceeds apps.

Cheers,

Ants

 

[Daydreamer]

I don’t know of any apps for real time currents.

Dial a Bouy is good for getting wind and wave state offshore before getting out there.

Tide talks with Kame Richards helped a lot. Happens once in a while at the Bay Model.

NOAA predictions are an average and can’t foresee how much storms and snow melt is going to reinforce the ebb.

 

[BobJ]

As described elsewhere on this forum, I use AyeTides on my iPhone and iPad for detailed current information. As you zoom in, increasing numbers of reference points appear on the chart. No doubt many are interpolated from a fewer number of actual measurement stations. The points marked “C” on the chart are for current.

I also keep Boat Speed and SOG on the instrument displays. Assuming BSP is calibrated, comparing the two speeds gives you real-time awareness of how the current is affecting your forward progress. Of course, SOG is just as accurate in reverse…

 

[NATBF]

I originally posted this because I saw, somewhere on the SSS forums, discussion of a very good (but not free) current app, but cannot find it. (Subsequent edit: maybe AyeTides BobJ just posted about; many thanks!)

--> If this rings a bell with you, please post the name.



Separately, I appreciate the advice to just use instruments/eyes, and Kame Richard’s presentation is excellent. Certainly there is no substitute for knowledge built over years. However, if I remember, Kame’s talk references the old print tidal current charts -- essentially what an app could provide. For planning, and for those of us new to an area of the bay, apps and web data seem natural resources to take advantage of.



====
Below are some resources I have come across, in the spirit of a resource for anyone that stumbles on this thread:

Apps:

Baycurrents (free)
Graphical current predictions in bay in pinch-to-zoom interface. Prediction up to 48 hours into the future, based on harmonic predictions plus various NOAA observation data (so should catch, e.g., extra current due to storm water outflows). Seems to match the NOAA Operational Forecast System predictions fairly well. (iPhone/Android; NOAA and Monterey Bay Aquarium Research Institute)
https://apps.apple.com/us/app/baycurrents/id1591997070
https://www.cencoos.org/information-solutions/san-francisco-baycurrents-app/

NOAA Buoy Data (not free – private app):
Possibly these replace the dial-a-buoy / provide the same info from an app. There seem to be a few of these apps; I have tried none. See, e.g.:
https://apps.apple.com/us/app/noaa-buoy-and-tide-data/id292148184

AyeTides (not free)
Added in response to BobJ's post (above; many thanks!); maybe this is the one I was looking for. Unclear if it is harmonic data or improved forecast -- I'll see if I can find out.

Web:

Improved current forecasts:

Better data than the harmonic predictions (based just on sun/moon/etc); all seem to match for SFB1201, which is about midchannel south of Pt Diablo:

NOAA:
https://tidesandcurrents.noaa.gov/map/index.html?id=SFB1201
From the basic site you can choose, ‘Data Type’ = ‘Current Predictions’ and get the better (’nowcast’) current data; from that tab you can choose ‘More Data’ = ‘Forecast Data’ to get the nice charts; see next link where I did this:

** (best): NOAA OFS forecast system
https://tidesandcurrents.noaa.gov/o...y Entrance&ofs=sfb&stnid=SFB1201&subdomain=en
Very nice graphical charts, showing the harmonic predictions (based on moon, sun etc. only; what you get at the normal tide/current table sites including NOAA) but also forecast/”nowcast” guidance based on additional immediate data. Looks like the forecasts matches the additional data well, and (e.g. right now, 4/3/23) matches the extra ~ 1 kt of outflow from all the rain, and how that increases ebb and almost cancels the flood. Note chart gives current speed, not direction; you need to determine whether that is ebb/flood (that’s what curve looks rectified). Example; note how outflow is 1kt high and inflow is almost canceled out compared to harmonic prediction, presumably due to spring runoff:

** (very good): L-36 (free)
Insanely nice site and a real service to the community; however, link to its current predictions does not seem to be on the front page for some reason. Seems site uses a single real-time current station and then does a look-up based on the best match previous bay data that matched that single station. This should be less accurate than the NOAA nowcast above, but the graphs are really nice, and seem to match OK for the one day/place I checked. Probably worth checking both.
https://l-36.com/sf_current_new2.ph..._year=2023&target_hour=16&target_min=00&map=1

Just the harmonic data:

DeepZoom (free)
https://deepzoom.com/
Very nicely done graphical current and other data. Says it’s just the NOAA harmonic data (i.e. not updated); unlike BayCurrents app, shows only the actual station points (does not interpolate), but does give current numerical velocities as well as vectors in a nice way. However, this seems not to be data with additional (e.g. runoff flows) incorporated. L-36 site is slightly less easy to use, but data at L-36 is at least somewhat matched to a real current station, per the site.

The online NOAA tidal/current predictions I naively thought were more accurate than printed tables (e.g. https://tidesandcurrents.noaa.gov/noaacurrents/Predictions?id=SFB1203_18), are clearly not updated for additional data (as it says somewhere – these are just the harmonic predictions).

Print:

Tidal Current Charts for San Francisco Bay (US Dept Commerce, Serial # 484, 5th ed., 1953
https://archive.org/details/TidalCurrentChartsSFBay
Worth mentioning are these the old charts for the bay, as shown (at tiny scale) in many tide/current books for the area. Nice full color larger scale ones (and with more time points) can be found in the PDF of the original document, linked above. Worth having; obviously do not include additional data like runoff.