One can draw such things but as Uwe Ziegenhagen says it is a lot of efforts. (Doesn't take hours but certainly more than 10 minutes.) The main problem with such figures is that one is never really done, there is always something that you can tune more.
\documentclass[tikz,margin=3mm]{standalone}
\usepackage{siunitx}
\usetikzlibrary{patterns}
\begin{document}
\begin{tikzpicture}
\draw (0,4.5)--(0,0)--(2,0)--(2,4.5);
\draw (0,0) rectangle (2,4);
\foreach \i in {0.2,0.6,...,3.9}
{\draw[ultra thin,cyan,dash pattern=on 4pt off 4pt] (0,\i)--(2,\i);}
\foreach \i in {0.4,0.8,...,3.9}
{\draw[ultra thin,cyan,dash pattern=on 4pt off 4pt,dash phase=4pt]
(0,\i)--(2,\i);}
\draw (-1,0)--(3,0);
\fill[pattern=north east lines] (-1,0) rectangle (3,-.2);
% Do something with the diver at (1,1)
\draw[very thin] (1.5,3)--(2.5,3.1) node[right,align=left,font=\footnotesize] {
sea water\\
(density 1020 \si{kg.m^{-3}}\\
or 1.02 \si{g.cm^{-3}})
};
% \draw[red] (0,0) grid[step=0.1] (2,2);
% \draw[red,thick] (0,0) grid[step=1] (2,2);
\begin{scope}[fill=white]
% back leg
\filldraw (1.7,0.8) to[out=180,in=-30] (1.3,1)
to[out=150,in=-20] (1,1.1) -- (1,1.15) -- (1.1,1.15)
to[out=0,in=150] (1.3,1.1) to[out=-30,in=-150]
(1.4,1.05) to[out=30,in=130] (1.5,0.95) to[out=-40,in=150] cycle;
% front leg
\filldraw (1.6,1.3) to[out=175,in=20] (1.3,1.3) to[out=-160,in=30] (1.2,1.2)
to[out=-150,in=0] (1,1.1) to[out=180,in=-20] (0.7,1.2)
to (0.75,1.4) to[out=0,in=150] (1,1.2) to[out=30,in=-120] (1.3,1.4)
to cycle;
% belt
\filldraw (0.7,1.2) to (0.75,1.4) to (0.71,1.42) to (0.66,1.22) to cycle;
% belly
\filldraw (0.66,1.22) to[out=180,in=-20] (0.5,1.23) to (0.71,1.42) to cycle;
% torso
\filldraw (0.71,1.42) to[out=-100,in=0] (0.55,1.2) to[out=180,in=-30]
(0.35,1.3) to[out=150,in=-90,looseness=0.4] (0.3,1.4)
arc(270:30:0.1 and 0.11) to[out=-60,in=180] cycle;
% hand
\draw[fill=black] (1.05,1.22) -- (0.95,1.2) arc(-90:90:0.02) --
(1.05,1.24) arc(90:-90:0.01) --
cycle;
% arm
\filldraw (0.95,1.2) to[out=170,in=0] (0.45,1.35)
to[out=180,in=170,looseness=1.2] (0.45,1.45)
to[out=-10,in=160] (0.95,1.25) to[out=-20,in=-10,looseness=1.2] cycle;
% oxygen
\filldraw (0.8,1.4) to (0.5,1.45) to[out=160,in=160] (0.55,1.55)
to (0.82,1.5) to cycle;
% googles
\draw[thick] (0.38,1.58) -- (0.2,1.5);
\fill[black] (0.19,1.46) arc(-70:110:0.03) -- cycle;
% tube
\draw[double,line cap=round] (0.23,1.45) to[out=-90,in=-70,looseness=1.6] (0.3,1.45) --
(0.26,1.7);
\end{scope}
\draw[very thin] (1.1,1.2)--(2.5,1.4) node[right] {diver};
\end{tikzpicture}
\end{document}
