You can go to the posted coordinates if you really want to, but you don't have to. What's more, it would require equipment that isn't listed in the cache attributes.
However, if you were to go there and look around, you would see a prominent structure placed as an aid to (nautical) navigation - one which is reachable on foot. Go there. On foot. (Note that bicycles are not permitted).
(No, really. Please don't ride your bike here, the area is for pedestrians and signed as such.)
Once you get there, count the number of bolts that secure this structure to its concrete pedestal. Let this number be X.
Now look around, you will see a row of posts... you might consider these as aids to pedestrian navigation at a certain time of day. Retrace your steps, passing X posts.
Now look to your left. You will see two different letters, painted to aid returning sailors to their proper berth. Sum the DRs (DR=digital root) of these two letters, let that sum be Y. If you have trouble with finding the letters, check the hint.
Walk past X more "aids to pedestrian navigation", and then almost to the next one. Nearby you will find one of several remembrance trees planted in the park. Who is being remembered? Let the DR of their name be Z.
To find the cache:
North decimal minutes = posted - (y * 10)
West decimal minutes = posted + (x * 100) - y + z
While a flashlight is not strictly required, it will make your life easier, at any time of day.
Please leave the stamp in the cache, it is not a trade item. BYO pen & stamp pad. Congrats to Fee&Me for their first-ever FTF prize on my first-ever hide!!