Ballast Water Management Decision Support System Model Application - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 269

- 60 nautical miles for vessels sailing from Vela Luka;

- 30 nautical miles for vessels sailing from Split;

- 30 nautical miles for vessels sailing from Vasto;

- 20 nautical miles for vessels sailing from Ortona; and

- 15 nautical miles for vessels sailing from Šibenik.

Figure 7 shows that vessels from all source ports outside the Adriatic Sea and
most source ports in the southern Adriatic (e.g., Bar, Bari, Brindisi, Duress and
Manfredonia) would not need to deviate from their intended routes to conduct BWE
in the designated BWEA. The option to require small deviations to gain longer route
distances through the BWEA were recognised in the cases of the source ports Bar
and Bari. Vessels sailing from source ports in the central Adriatic (e.g., Šibenik,
Split, Vela Luka, Ortona and Vasto) to the Port of Koper would need to deviate more
substantially to gain relatively short route-lengths in the BWEA.
The most critical are vessels sailing to the Port of Koper from the ports situated
north of the BWEA, i.e., northern Adriatic. When their ballast water intended for
discharge poses an extreme risk according to the DSS these are not allowed to
discharge unmanaged ballast water. The applicability of BWE as the BWM method
is considered inappropriate on these routes especially because of very shallow
waters (i.e., mostly <24 m depth) and the close proximity of their intended routes to
the shore (i.e., <30 nautical miles). On the other hand such very enclosed sea area is
very safe for sailing, hence vessels may sail in minimum (light) ballast condition,
possibly without loading extreme risk water or to load only a quantity that would
not need to be discharged, but still considering the vessels' minimum safety
requirements, e.g., stability, propeller immersion. The vessels considered in 2005
would not be able to sail without ballast. However, instead of using vessels, the
cargo could also be transported by barges without doing ballast operation, which
was already in practice for the same cargo at these routes years ago. Technically 3
the option to substitute vessels with barges exists. Unfortunately, this is not a feasible
BWM option for the selective approach because the DSS decision is taken after the
BWRF is submitted, i.e., after ballast water is already loaded on the relevant vessel.
Therefore, all vessels discharging ballast water from the source ports which are
situated north of the BWEA are excluded from the assessment.

Time and Distance Needed to Complete Ballast Water Exchange

Certain large vessels need up to 2 days in navigation to complete full BWE. At a
speed of 15 knots this would mean that more than 700 NM voyage length may be
needed to complete BWE. However, the length of the required route to complete

3 This approach has also other implications (e.g., availability, fi nancial) that would need to be
studied fi rst.