The verb for navigational is navigate.

As in "to navigate a course".

navigate

The abstract noun forms of the verb to navigate are navigation and the gerund, navigating.

The verb of navigation is navigate.
Other verbs depending on the tense you need is navigates, navigating, navigated.

Some example sentences are:
"I will navigate the boat".
"She navigates through the asteroid belt".
"We are navigating through the new system".
"They down navigated the river".

This inlet is difficult to navigate, even during high tide.

You drive; I'll navigate.