NavList:

David McN:

Since you're describing this traverse table, tabulated at quarter-degree intervals, as "compact" compared to Norie's, I'm going to guess that its compactness comes from having the distance column headers always being 1-5 on the left-hand side and 6-10 on the right, and for something like a distance of 16 you're expected to look up the values for both 10 and 6 and add them together.

If that's the case, then your problem isn't "Find a row that has one entry closest to your desired value" but "Find a row that has two entries that add to a sum closest to your desired value."  That's... yikes. 

There will probably be particular situations where arithmetic shortcuts present themselves if you look for them, but I personally can't think of a one-size-fits-all method that would reliably save time over computing the answer directly, either graphically or with trig tables.

But for a start, unless you're actually trying to steer to the nearest quarter-degree, you might want to go through the table and highlight all the rows for whole degrees and get into the habit of only searching those hightlighted rows.  The bold numbers in the row headers aren't much of a help if you're searching in the table body directly.

--David Iwancio