What type of watercraft is the life preserver on?
The life preserver is on the boat.
    src        edge_attr  dst
0     0               on   11
1     2               on   14
2     2   to the left of    5
3     2   to the left of    6
4     3  to the right of    4
5     3   to the left of    6
6     3   to the left of    5
7     4   to the left of    5
8     4   to the left of    3
9     4   to the left of    6
10    5               on    6
11    5  to the right of   14
12    5  to the right of    2
13    5  to the right of    3
14    5  to the right of    4
15    5   to the left of   11
16    6  to the right of   14
17    6  to the right of    4
18    6  to the right of    3
19    6  to the right of    2
20    6  to the right of   15
21    6   to the left of   17
22    6   to the left of   11
23    7               on   12
24    7               in   12
25    7   to the left of   16
26    7  to the right of    8
27    7   to the left of   10
28    8   to the left of    7
29    9   to the left of   16
30   10  to the right of    7
31   11  to the right of   14
32   11  to the right of   13
33   11  to the right of    6
34   11             near   17
35   11  to the right of    5
36   13   to the left of   11
37   13  to the right of   14
38   14   to the left of   11
39   14   to the left of    6
40   14   to the left of   13
41   14               in   12
42   14   to the left of    5
43   15       hanging on   14
44   15   to the left of    6
45   16               by   11
46   16  to the right of    9
47   16  to the right of    7
48   17               in   12
49   17             near   11
50   17  to the right of    6
51   17               on   12