USGS Hi-Res Underwater Topos

I wanted to share a really cool resource I've been using to find reefs and interesting structure to target when fishing inshore and offshore CA waters. The site is a little clunky but super cool once you fudge around with it.

The USGS is working on the California Seafloor Mapping Program and all of the data is public and available online. One of the data sets is "Colored Shaded-Relief Bathymetry" i.e. renderings of the underwater structure offshore in CA. It super interesting to look at, but also really useful for choosing spots to fish.

How to use it:
*Follow link- https://pubs.usgs.gov/ds/781/
*Click on the red square that represents the area you'd like to look at
*Click "more info" next to "sheets URL"
*Click "Sheet 1" (this is usually the shaded bathymetry map)
*PDF loads, and you have a hi-res underwater seafloor map.

Some areas are not complete yet (much of SoCal, channel islands) but NorCal seems to be mostly complete.

The image below is a snapshot of Bodega Bay, the second one is under the Golden Gate. Contour lines are in meters. The resolution is pretty stunning once you zoom in on it.

Enjoy!

Sweet! Thanks!

Thanks for the heads up on this!!  I'm going to play with this as a side project to create an interactive map with the raw GIS data. 

Wow wicked cool! I've been studying inshore charts but resolution is limited.

My buddies tell me about several "buckets" that are worth checking out but since I don't have a fancy gps I don't really find them. I imagine in ArcGIS I could probably find a couple coordinates and enter them into my Garmin.

Tedski I'm curious what you have in mind as far as interactive maps. I usually do plant stuff and have used ArcCollector remotely but think it would be rad to merge my appreciation for fish and underwater habitat with mapping tools. Guess one limitation is the that touch screens on a kayak would be annoying.

Despite swales and rocky reef any other thoughts? Any knowledge of sat imagery use in determining aquatic vegetation? Fun stuff!

Very cool!

Wow wicked cool! I've been studying inshore charts but resolution is limited.

My buddies tell me about several "buckets" that are worth checking out but since I don't have a fancy gps I don't really find them. I imagine in ArcGIS I could probably find a couple coordinates and enter them into my Garmin.

Tedski I'm curious what you have in mind as far as interactive maps. I usually do plant stuff and have used ArcCollector remotely but think it would be rad to merge my appreciation for fish and underwater habitat with mapping tools. Guess one limitation is the that touch screens on a kayak would be annoying.

Despite swales and rocky reef any other thoughts? Any knowledge of sat imagery use in determining aquatic vegetation? Fun stuff!

I wasn't thinking something you'd use on the water, but that's also a good idea!  I was looking at the raw gis data and it lacks the colorized, so I was thinking of a way to colorize on an interactive (scrollable, zoomable) map.

Thanks for sharing! Here's another tool I frequently use (similar to Navionics). In addition to depth, it also gives you the makeup of the ocean floor.

http://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-marine-charts-navigation.html#12.94/37.8769/-122.6737

Wow wicked cool! I've been studying inshore charts but resolution is limited.

My buddies tell me about several "buckets" that are worth checking out but since I don't have a fancy gps I don't really find them. I imagine in ArcGIS I could probably find a couple coordinates and enter them into my Garmin.

Tedski I'm curious what you have in mind as far as interactive maps. I usually do plant stuff and have used ArcCollector remotely but think it would be rad to merge my appreciation for fish and underwater habitat with mapping tools. Guess one limitation is the that touch screens on a kayak would be annoying.

Despite swales and rocky reef any other thoughts? Any knowledge of sat imagery use in determining aquatic vegetation? Fun stuff!

I wasn't thinking something you'd use on the water, but that's also a good idea!  I was looking at the raw gis data and it lacks the colorized, so I was thinking of a way to colorize on an interactive (scrollable, zoomable) map.

Tedski, haven't thought about implementing, but I'm imagining one thing that I could do is create layers of cool features from the raw data, and upload to arcGIS online and save an offline map, so I can have real time location on the water. I'm going to take a look at the raw data on my work machine.. very interesting to me.

Thanks for sharing! Here's another tool I frequently use (similar to Navionics). In addition to depth, it also gives you the makeup of the ocean floor.

http://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-marine-charts-navigation.html#12.94/37.8769/-122.6737

Wow that is so cool. Thanks for sharing! Wish we could input this onto a GPS device and scroll in and out OTW.

Thanks for sharing! Here's another tool I frequently use (similar to Navionics). In addition to depth, it also gives you the makeup of the ocean floor.

http://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-marine-charts-navigation.html#12.94/37.8769/-122.6737

Wow!! Amazing to see.  Thank you for sharing.  The shallow depths in so many areas surprised me but then again, i have never fished the bay

Does anyone know if the pdfs are georeferenced?  If they are, you could put them on the avenza app on your phone.  It's a great app that does one simple thing:  Shows you where you are on a geoPDF or GeoTIFF if you are in fact on the map.  I use it for work all the time, and it would be a great simple way of seeing where you are on these maps.

I will probabbly try this at some point and can get back to you all on it if I do.

This is awesome, thanks! Rikk Kvitek (map maker for many of these) was my GPS/GIS professor at CSUEB 6-7 years ago. He was kind of an ass but he is smart and good at his job 

He was kind of an ass ...

I hear that a lot of college profs are like that...

I tested the PDFs in Avenza, and they do not appear to be georefetenced.  Surprising that USGS would produce them that way as most his and cartography software makes this easy, but there you go.

I may download the underlying data, put it in qgis, and make my own geoPDF at some point for my areas of interest, if I do I'll report back on how it goes.

I tested the PDFs in Avenza, and they do not appear to be georefetenced.  Surprising that USGS would produce them that way as most his and cartography software makes this easy, but there you go.

I may download the underlying data, put it in qgis, and make my own geoPDF at some point for my areas of interest, if I do I'll report back on how it goes.

Would be really interested in knowing how that goes! Please do report back! I'm not super good with GIS software so my best idea was blowing up one of the PDFs, translating lat/lon lines and then plugging coordinates in the the Garmin haha...

Ok, after a beautiful morning off Capitola yesterday that resulted in a catch of... 2 smelt, I decided to mess with this to have a good way of finding the reefs besides my surf / dive experience and the kelp (which is sparse on the deeper reefs).  Results attached.  I used the offshore aptos "presumed benthic habitats" layer, which shows the reef and different types of sand / gravel sediment.  The map could used some prettying up, but it is georeferenced and can be imported into the avenza app (which is free) to see where you are on it on your phone.

I am going to mess with the bathymetry and hill shade rasters more, the way they displayed a combo the base bathymetry and the hill shade is difficult to duplicate, but I may figure it out.  It would be good to have both the habitat map and the bathymetry one.  I'll probably do a few more Santa Cruz area ones if people are interested.

Looking forward to trying it out on my next trip.