MnrAq

Annex 5 245
uncertainties (standard deviation of approximately 13% of mean) being for well observed (on AIS) fleets, and
those fleets where the total number of ships listed in IHSF closely matches the number of ships observed
on AIS (cruise ships, large vehicle carriers, large tankers and bulk carriers and large container ships). This
contrasts with the smallest size general cargo fleet and the smallest tankers (both 0–5,000 dwt), which have
standard deviations exceeding 20% of the mean estimate. The contrast is even more notable for certain
categories of non-merchant shipping (e.g. “Miscellaneous – fishing” and “Miscellaneous – other”: 37% and
56% respectively), which are poorly observed and poorly matched in IHSF, although in both cases these are
ship types and sizes which are not categorized in this study as international shipping.
Table 21 – Estimated characteristics of the uncertainty for individual ship type and size categories
Ship type Size category Mean Standard Deviation
Standard deviation
as a % of mean
Bulk carrier 0–9,999 4,484,703 783,207 17%
10,000–34,999 23,406,255 3,572,119 15%
35,000–59,999 43,016,318 6,617,266 15%
60,000-99,999 44,617,850 6,411,213 14%
100,000–199,999 35,363,715 5,188,630 15%
200,000–+ 10,478,638 1,494,526 14%
Chemical tanker 0–4,999 4,493,655 679,510 15%
5,000–9,999 7,007,269 956,839 14%
10,000–19,999 12,117,662 1,744,680 14%
20,000–+ 29,614,933 4,314,846 15%
Container 0–999 12,289,773 1,599,989 13%
1,000–1,999 30,532,084 3,913,000 13%
2,000–2,999 24,649,848 3,352,376 14%
3,000–4,999 52,578,459 6,509,096 12%
5,000–7,999 42,436,722 5,480,776 13%
8,000–11,999 30,009,753 3,925,368 13%
12,000–14,500 8,614,072 1,120,637 13%
14,500–+ 776,608 105,888 14%
General cargo 0–4,999 17,993,881 3,891,076 22%
5,000–9,999 15,937,373 2,326,828 15%
10,000–+ 26,463,128 3,720,868 14%
Liquefied gas tanker 0–49,999 10,477,872 1,501,513 14%
50,000–199,999 28,390,114 3,641,861 13%
200,000–+ 5,313,632 697,094 13%
Oil tanker 0–4,999 11,244,284 2,391,743 21%
5,000–9,999 4,339,055 580,383 13%
10,000–19,999 2,038,769 260,104 13%
20,000–59,999 12,307,094 1,696,973 14%
60,000–79,999 9,870,325 1,326,081 13%
80,000–119,999 25,724,409 3,405,958 13%
120,000–199,999 16,846,138 2,271,416 13%
200,000–+ 35,612,562 4,762,621 13%
Other liquids tankers 0–+ 631,061.4 222,835 35%
Ferry – pax only 0–1,999 8,065,654 1,839,021 23%
2,000–+ 937,766.4 142,744 15%