Arguable would be a delicate and polite way of saying it.

"True. I'd risk saying there aren't that many sharks in the streams near Tirion. I'd suspect they might need more wiggle room than a stream can provide."

Though he has to admit it would be quite a sight. Probably one certain to cause many a heart-attack, metaphorical or not, in elves of less adventurous disposition. Fëanor finds this thought incredibly amusing for all the wrong reasons.