Hull fouling

Implications of stricter biofouling standards

Published: 04 May 2023

Tankers can spend days, if not months, idle on storage duties accumulating underwater growth, which could be an expensive issue now ports and terminals are becoming increasingly sensitive to underwater fouling.

This article is reproduced by kind permission of Riviera Maritime Media. See the original article.

The tougher application of rules to reduce the number of vessels presenting in Southern Hemisphere ports with hull fouling is setting a trend that is likely to spread globally, and could have a costly impact on tankers for whom long periods idle are an accepted part of the economic cycle. But a more aggressive application of clean hull rules not only has a positive benefit on reducing the spread of invasive species – a cleaner hull reduces fuel consumption and is a positive and relatively inexpensive way to reduce emissions.

In Australia, stricter biofouling rules came into force June 2022, and these are applied in an educational way, explained BIMCO maritime safety and security manager Ashok Srinivasan in the 11 April 2023 webinar, Navigating new biofouling requirements: strategies for clean hulls and avoiding fouling.

In New Zealand, anti-fouling laws have been in place since 2018, and BIMCO has produced a booklet on the issue. The main issue is the status of the anti-fouling in Australia and New Zealand, “As an international organisation, BIMCO believes regulations should be international, because shipping industry itself is international,” he said.

“But in its absence, we have a regulation that benefits the coastal states.” This has the impact of raising the bar, in that the companies that operate in the region have had to raise their standards to meet the local requirements.

In this respect, the active application of the fouling regulations in the region benefits the first movers in biofouling and negatively impacts those that had been saving costs by not undertaking fouling removal, “It leaves them no option but to comply,” said Mr Srinivasan.

There is a wider issue in that a ship arriving in the region with a foul hull cannot clean there but must go elsewhere to clean the hull. Mr Srinivasan made the point that if this rule is applied across several regions, then where is the cleaning to take place?

The issue of biofouling is currently under review at IMO and Mr Srinivasan hoped the outcome would be a series of guidelines that included hull cleaning with capture at the core.

Presenting at the same webinar, HullWiper Ltd managing director Simon Doran noted there is evidence the application of hull anti-fouling regulations does have an impact on reducing the spread of invasive species, which was the original purpose of the regulations.

The added benefit is, “Hull cleaning is the low-hanging fruit to reduce the carbon footprint,” said Mr Doran. But there is an important distinction to be made with the process. As a hull cleaning provider, Mr Doran believes there needs to be an understanding of the impact. Frequent grooming of the hull through a proactive approach without an assessment of the fouling could damage the coating. “It defeats the object,” said Mr Doran.

“Which is why I believe reactive cleaning, however aggressive it may have to be, but with a collection system, is presently the only way to go.”

Leading the charge are the ROV’s which Mr Doran noted can clean up to 97% of the underwater surface area of a ship. This greatly increases the safety by reducing the need to have divers in the water, but as a diver himself, he recognised the technology had not yet eliminated the need to have divers clean the niche areas of the ship.

Mr Doran noted shipping companies can do more to prevent falling foul of regional antifouling regulations – a simple data gathering inspection using an ROV before leaving the last port could be sufficient evidence to show the hull is clean.

BIMCO has a hull fouling clause for application in a charter party, which aims to distribute the costs associated with the hull cleaning between the owner and the operator. One issue that arose is that hull cleaning companies are not certified by class, making it difficult to assess the professionalism of the companies involved. Mr Doran noted that a review of the ISO quality control certificate was to establish a company’s credentials. He was also in favour of using saltwater cleaning over brushes, which can leave micro-abrasions in the coating.

Mr Doran noted the detection of fouling did not always require a physical inspection. There is sophisticated software provided by the coating manufacturers and third parties which monitors and alerts the operator when the vessel’s performance has degraded since the last recoating or hull cleaning. This is a positive way to identify the need for cleaning.


Webinar poll results

How do you regard New Zealand’s biofouling regulations and requirements?

They are highly effective and fit for purpose 13%

They are somewhat effective, but could be improved 34%

They are adequate, but could be more clearly defined 28%

They are somewhat inadequate and could be more practical 25%

They are completely inadequate and not fit for purpose at all 0%

If the new guidelines require ships to conduct frequent inspections and cleanings, which will raise the operational cost, will shipping companies still go with expensive anti fouling coating that prohibits fouling growth, or favour cheaper options that offset the cost and clean once a year?

Despite the increase in cost, we will continue to invest in the best (and expensive) anti fouling coatings 50%

While we would like to have the best anti-fouling coating, increase in inspection costs is a problem and we would lean on saving costs, by investing in alternate medium quality, lower cost products 20%

If ships are pushed for more frequent inspections and cleanings, it does not make sense to have the expensive anti-fouling coating in place, therefore, we will go for the cheapest anti-fouling coating and comply with the regulations in terms of cleaning and inspection 30%

Who should be responsible for paying for hull cleaning?

The shipowner 30%

The ship manager 6%

The ship charterer 36%

The ship operator 18%

The coating company 10%

Source: Riviera Maritime Media

Ashok Srinivasan


Ashok Srinivasan

Manager, Maritime Safety & Security

Singapore, Singapore