What's located on top of the boat?
The crane is on top of the boat.
    src        edge_attr  dst
0     0   to the left of    4
1     0   to the left of    8
2     0   to the left of    7
3     0  to the right of    6
4     0   to the left of   15
5     1   to the left of   15
6     1   to the left of    8
7     1   to the left of    7
8     1  to the right of    6
9     4  to the right of   11
10    4   to the left of   16
11    4  to the right of    0
12    5            below    7
13    6   to the left of   11
14    6   to the left of    1
15    6   to the left of    0
16    7  to the right of   11
17    7  to the right of   13
18    7  to the right of    1
19    7        on top of    5
20    7  to the right of    0
21    8        on top of    7
22    8  to the right of    0
23    8  to the right of    1
24    8  to the right of   11
25   10  to the right of   13
26   10   on the side of   12
27   11   to the left of    8
28   11   to the left of    4
29   11   to the left of   15
30   11  to the right of    6
31   11   to the left of    7
32   12  to the right of   13
33   13   to the left of   10
34   13   to the left of   12
35   13   to the left of    7
36   15  to the right of   11
37   15   to the left of   16
38   15  to the right of    0
39   15  to the right of    1
40   16        on top of    7
41   16  to the right of   15
42   16  to the right of    4