Iphikrates as a Marine?

[Akontist]

I'm trying to remember the source for a story about Iphikrates from long before his rise to fame - as I recall the story, he served as a marine on an Athenian trireme and engaged in some act of bravery that attracted the attention of others or perhaps earned for himself the award for valor.  But I can't recall the source for the story and I may even have misremembered it all together.  Maybe it wasn't even Iphikrates?  If you know, please set me straight.

Thank you.