interreg 
Baltic Sea Region 
JROPEAN 
Z6I0MAL 
*VELOPMENT 
aD. 
rı COMPLETE PLUS 
Table 5: Overview of IWC methods for ships (modified after Watermann et al. 2021). 
Method 
Technique 
Application 
Benefit 
Risk 
Costs 
Availability 
Diver operated cleaning 
device 
Rotating brushes, 
High pressure-jetting, 
Blades 
- with external capture and 
filtration 
Hull and niche if accessible 
Effective, control of cleaning 
effort, access to most 
niches, optical control 
Application only in ports or 
sheltered waters without 
waves, currents, and 
turbidity 
high 
Baltic Sea ports depending 
on permits 
ROVs 
Rotating brushes, 
High pressure- 
jetting, with internal 
capture by filtrating 
bags 
Hull 
Effective, control of 
Zleaning effort, optical 
control 
Application only in 
ports or sheltered 
waters without waves 
and currents. Control 01 
bag capacity limit 
needed. 
|IOWw 
Baltic Sea ports 
depending on permits 
Ship-based ROVs 
Rotating brushes 
Hydro-jetting 
& 
Hull 
Effective, control of 
cleaning effort, 
optical control 
Exclusively 
applicable on 
biofilms, no capture 
of organisms and 
paint particles 
high 
Everywhere when 
laying idle in calm 
waters depending on 
permits 
4 Recommendation for IWC procedures in the BSA 
This paper suggests four different recommendations for IWC procedures in the BSR (table 6) 
which is also visualized in the flow chart (Appendix 1). IWC may be considered allowed 
1. without any further restriction or inspection (green) 
2. when the fouling material is captured and filtered (yellow) 
3. if the fouling material is captured and filtered plus explicitly filtrating biocides and/ or a prior 
chemical risk assessment (orange) 
4} 
(9