What are the crates on?
The crates are on the boat.
    src        edge_attr  dst
0     0               in    1
1     0               on    1
2     0               on   13
3     0               by   13
4     1  to the right of    2
5     2               on    0
6     2   to the left of    1
7     3   to the left of    5
8     3   to the left of    4
9     4  to the right of    5
10    4  to the right of    3
11    5               on    0
12    5  to the right of    3
13    5   to the left of    4
14    6               of    0
15    8               in    0
16    8               on    0
17    9               of    0
18   10               of    0
19   12               on    0