In this problem, a diver drops to the water from a height of $h = 46~mathrm{m}$. His gravitational potential energy drops by $Delta PE_text{gravity} = 25000~mathrm{J}$. We find the weight of the diver.

The change in potential energy is equal to the weight $w$ of the diver and the height $h$. We have

$$
begin{align*}
Delta PE_text{gravity} &= wh \
implies w &= frac{Delta PE_text{gravity}}{h} \
&= frac{25000~mathrm{J}}{46~mathrm{m}} \
&= 543.47826~mathrm{N} \
w &= boxed{ 540~mathrm{N} }
end{align*}
$$

$$
w = 540~mathrm{N}
$$