Puffin, the place to end:
http://coastwatch.pfeg.noaa.gov/coas.../CWBrowser.jsp
When you master this browser program, you don't need to look anywhere else. There is a learning curve, but if you play with it enough you'll get good at it.
12 Step Mini-tutorial
Click on the link above:
1. Just below "1) Select a region:" you will see "(or specify ...)" and type in these coordinances just for now. Important: DO NOT HIT THE ENTER KEY YET. Max Y: 45.5 Max X: -125.2 Max X: -123.8 Max Y: 44.5
2. "3) Select a size:" Select "Large"
The Map will increase in size and have in your coordinances. Another way to adjust the coordinances on the map is to hit the ENTER key when the cursor is in one of the coordinance fields. Example: Where you typed in 44.5, put the cursor in that area and click the left mouse button, then hit the ENTER key.
3. In the green Edit: bar on top select "Contour Data."
4. "Select a data set:" Bathymetry, ETOPO2v2, 0.033333 degrees, Gobal
5. "2) Select a color:" I like white
6. "3) Draw lines at:" I erase everything except for "-100" and then hit the ENTER key.
7. In the green Edit: bar on top select "Grid Data."
8. This is where you just have to play around.
9. Try this: "1) Select a data set:" Scroll to the top and select "Chlorophyll-a, Aqua MODIS, OSU DB, 0.0125 degrees, West US*"
10. "2) Select a time period:" If one day doesn't draw anything select "3 day" and so on until you have color. For fishing tomorrow "pass" would be the best but most of the time we are not that fortunate.
11. "3) Select a centered time (GMT):" Make sure the latest date is selected.
12. "5) Scale:" I'll usually leave "Min:" alone and put 3 in for the "Max:"
Most of the time I'll leave "The Map" to "Standard" size and when everything looks to my liking then I'll go back and make the map "Large."
I used Chlorophyll for the example because temperature is actually easier.
The temperatures lately have all been good temperatures for tuna. One thing has become very clear this year especially: Chlorophyll is at least as great of importance as temperature. Personally I feel chlorophyll content and the resulting breakline is more important. More times than not a chlorophyll break is also associated with a temperature break which equals perfect. Research shows that the "Transition Zone" or "TZ" is .2 mg m^-3 and tuna spend the majority of their time in those waters. They will feed in turbid water up to about 2 and perhaps 3 for periods of time.
Another thing to remember is this: 100 and 200 meters of water depth is important in the life of a tuna.