This is a play on the first cahe I found nearby with a similar name. When I saw the name, I initially though of the location that the coordinates take you to. It's a place to answer the question posed. It was 8.94 feet today. Maybe you can answer the question in your log. 
You should not have to step off the path at this part.
What is the highest possible measured level? let the number be AB.CD feet become A,B,C, and D. (Remove the decimal point) NOTE: A+B+C+D=11. If it get's this high, you probably won't get the cache as the area will be in a flood state. Note that in the wet season that this area can and has flooded so that the walking path is impassable.
Please no spoilers in your post please.
For the Final Latitude: Subtract the difference of CD-B from the Posted Latitude
For the Final Longitude: Add DC to the Posted Longitude. Or C to the D power.
This is a Signature only cache. Bring your own pen. You will step off the path here, but you may have wanted to anyways for a couple of reasons.
Congratulations to PDXJim as FTF