Answer
$38.6^{\circ}$
Work Step by Step
Find the angle of incidence in the air (relative to the normal) using Snell’s law. Here “1” designates air, and “2” designates water.
$$n_1sin\theta_1= n_2sin\theta_2$$
$$\theta_1=sin^{-1}(\frac{n_2}{n_1}sin\theta_2) $$
$$=sin^{-1}(\frac{1.33}{1.00}sin36.0^{\circ}) =51.4^{\circ}$$
This is the angle relative to the vertical. The angle of the sun’s rays as measured from the horizontal (i.e., the angle above the horizon) is the complement of that angle, $38.6^{\circ}$.