Brad: I've had a great idea for a new puzzle cache.
Janet: Another one? Oh well, what is it?
Brad: Well it's a play on words. I'll call it "Log this." Of course "Log" means to write in the logbook to log a find. But "Log" is also short for logarithm. So for the puzzle "Log" means to fing the logarithm of two numbers.
The Puzzle would be
Use these two numbers to get the decimal degree values for South and East
South 8.162065
East 4.0448276
To solve it they must find the "log" of each of those numbers
South: Log (8.162065) = 0.91180
East: Log (4.0448276) = 0.60690
Add those answers to 34 for South and 138 for East to get decimal degrees
S 34.91180°
E 138.60690°
which converts to
S34° 54.708 E138° 36.414 which is the cache location.
So "log this" fits both signing the logbook, and also solving the puzzle. A double meaning. A triple meaning if you add "logging the find" on line! A triple play on words! What could be better? 
Janet: Yes I see that. But what about all the people who prefer traditional caches and not having to deal with your twisted ideas?
Brad: What do you mean twisted?
Janet: Well, "Log this" and "Log this". It's just too convoluted. Too many logs. Some people won't bother. Why not just make it a trad?
Brad: But I like the puzzle.
Janet: Why not include the puzzle and solution so people can learn about your "logs" but still make it a trad?
Brad: Why can't I just do what I want?
Janet: Well you could. By the way, do you know the date today?
Brad: Um, my watch says it's Feb 14th.
Janet: And....
Brad: Oh! It's Valentine's Day!
Janet: So what do you think you should do?