Palindromic tugboat sound Crossword Clue

 The palindromic tugboat sound is TOOT.

A palindrome is a word or phrase that reads the same backward as forward. The word "toot" is a palindrome because it reads the same backward as forward.

Tugboats use the sound "toot" to signal to each other and to other boats. It is also used to warn people that the tugboat is approaching.

I hope this helps!