Ah HA! Amala will be saved! FEAR NOT, fellow elf rooter-forers! With my Red Mage-esque intellect, I have devised a brilliant plan for the elves! Here's how this'll go down... (cue the "Mission: Impossible" theme)
STEP 1: The elf who was previously commiserating with the turtle shall tell the turtle to go to the frogman covered barge. The turtle will bite onto the back of it, unnoticed by the frogmen, and act as dead weight. Given it's immense turtle-powers, I'm certain it will bring the froggy ship to a halt.
STEP 2: The bowelves will fire arrows, not at the barge, but at overhanging vines, cutting them in such a way as to drop a rope from their barge to the frog barge. The expert marksman will pin the far end of the vine to the other barge with an arrow as it falls. Another elf will grab our end of the vine.
STEP 3: Now here comes the tricky part; IT WAS ALL A DIVERSION! What actually happened was the turtle had salt put in it's mouth by one of the elves! He trickles it aaaaaaaall around the water, preventing other frogmen from swimming there! Then that one bad-ass what's-his-face will come up from the water, because he was using his reed straw to breath underwater.
STEP 4:At this point, bad-ass pops up and slices the main frogman's hand off, dips it in the salty water, and stuffs it into a stone bowl he was carrying. Angling it in such a manner that the blast (from the salt) shakes the frogmen off of the barge, into the non-salty water.
STEP 5: The awesome turtle will be wearing an elf's hat, tricking the disoriented frogmen into thinking it's an elf, and then lead them away. I mean, frogmen are pretty stupid to begin with. The elvish barge should have caught up with the S.S. Froggy by now, and then...
STEP 6: VICTORY!!!!
IT SHALL WORK! I CAN FEEL IT!