Does "flounder" work for sailboats?

Solution 1:

As mentioned in the comments both flounder and founder are appropriate words.

I think vocabulary.com gives a good overview of the differences.

Here is their overview of flounder.

A flounder is a fish, but as a verb, it means to blunder about, to be in serious trouble. In the following examples, something is struggling but hasn't completely failed...

Compared to their overview of founder.

A founder is someone who starts something, but as a verb, founder literally means "to sink." Figuratively, it's "to collapse or fail completely."

So if the student is merely struggling to stay afloat then you should choose flounder, but if they are completely over their head and drowning then founder is the better word.