Pretty good for the first time. Enjoyed it

I see you are doing a modern haiku,

I would recommend to write it as a note, so the readers will know it. As at least in this site, the majority are familiar with the traditional one: the 5-7-5 haiku.

I feel you did a good job capturing the scene. You created two pictures while at the same time reached the reader's ears.

I mean I could see the fisherman singing when suddenly there comes a gray mist, interrupting his song.

Another thing about the haiku is that it doesn't have any capital letters nor periods. I believe the only punctuation used is either these ; - : ,

Lol many but depends on how they are used within the poem. Just the period isn't use.
At least how I was taught.