Answer
The symbolic form of the provided argument is\[\begin{align}
& \,\,\,\,\,\,\,\,\,\,p\to q \\
& \frac{\,\,\,\,\,\,\,q\to r}{\therefore \,\,\ \sim p\to \sim r} \\
\end{align}\].
It is an invalid argument, where, p is I am at the beach, q is I swim in the ocean and r is I feel refreshed.