This I like and it speaks to your style. I tend to read the post of the same writers back to back as if their post were a chap book and sometimes it proves irrelevant to my appreciation or dislike of their work but today I am rewarded. Reading your works in sucession gives me a structured glimpse into your writing that has been reviting. 
If I were to give you some feedback about the poem I would simply say mortal is a word that is like interference in a ball game. I am going to muse over it but my first instinct calls it some what redundant. I like to know what you think it adds.------------Andy

I really liked the imagery in this.  I actually wrote a short poem years ago that was very similar in thought that I called Wavelength.  Maybe I'll post it here in the near future.  I only had one suggestion.  I would capitalize "Shores of Time" and the "Ocean of Eternity" as if they were proper names.  In my opinion it seems to add to the metaphor.

Shawn

Hi
I would end this without a mention of eternity. It is too oft used and it is implied.

I love the rythmn in this piece, very tidal

Try it maybe like this:

Life, mortal life 
is a tide 
that touches, fleetingly, 
the shores of Time.   
With force and vigor it arrives; 
leaping, surging, bouncing, 
frolicsome and noisy; 
puts up a brief spectacle, 
then ebbs away.

Thanks nas for your suggestions.

Thanks Daniel for your comments. I am happy you liked the poem.

Life, mortal life
is a tide
that touches fleetingly
the shores of Time. 
With force and vigor it arrives;
leaping, surging, bouncing,
frolicsome and noisy;
puts up a brief spectacle,
then ebbs silently
into the ocean of eternity.