Certain ports with high tidal ranges can leave vessels falling dry, meaning that they are not afloat when berthed and instead make contact with the seabed. This can pose several challenges, as vessels are not able to move and may also have limited cargo loading and unloading abilities. 

Not Always Afloat But Safely Aground Mean (NAABSA) is a clause in a charity party (charter agreement) between the shipowner (lessor) and the charterer (lessee), which specify that the chartered vessel may not always be afloat and is allowed to be resting safely aground when falling dry. 

An NAABSA clause in a charter agreement indicates that the chartered vessel is allowed to be berthed or moored at certain ports where there is a possibility that the vessel rests safely on the port basin.

This is different from the Always Afloat Always Accessible (AAAA) clause, which ensures that the vessel must always be afloat and is not allowed to make contact with the sea bed at any given time.

When a vessel falls dry, it has to be ensured that the port basin is:

  • Flat (no incline or decline)
  • Homogeneous (preferable mud or sand)
  • Void of Objects (free of rocks, piles, stones, etc)

It’s important that when a vessel rests upon the port’s basin, that its hull does not get damaged. Vessels that are able to facilitate this are usually designed with a flat bottom and reinforced hull. 

This article will take an in-depth look into the Not Always Afloat But Safely Aground Mean (NAABSA) clause, highlight the risks and also provide some information and useful tips to ensure dry falling is practiced safely. 

Not Always Afloat But Safely Aground (NAABSA) Clause & Wording

A charter party often includes an NAABSA clause, if the chartered vessel is expected to berth at ports that have high tidal ranges, whereby the low tides cause a vessel to fall dry. 

There are various ways to include and word this clause into a charter party. You may use below as a reference or take a look at one of BIMCOs clauses for this. 

Subject to the shipowner’s approval, the chartered vessel may fall dry and safely lie aground a safe berth. The Charterer takes all responsibility in ensuring that the berth basin is adequate and that the vessel does not suffer any damage during the process. 

The charterer also agrees to indemnify the shipowner for any damage, loss and costs that arise from direct or indirect consequences of falling dry. This may include but is not limited to inspections, assessments and repairs. 

Risks of Not Always Afloat But Safely Aground

There are inherent risks and challenges that a scenario like this poses to both the shipowner and the shipper, who leases the vessel. Let’s take a closer look at a few of these risks. 

  • Vessel May Not Be Movable – Once a vessel has made contact with the berth basin, it is not afloat. This means that the chartered vessel cannot be moved. Only during high tide can the vessel be operated, which can lead to additional charges and waiting time. 
  • Vessel May Require Inspection – Vessels must always be maintained and regularly checked for damage. When a vessel makes contact with the sea bed it may damage the hull, requiring additional inspections and assessments, which can be costly and inconvenient. 
  • Vessel May Incur Damage – Vessels that fall dry at NAABSA ports may experience damage to the hull, rudders, thrusters, and propellers. This often happens if it makes contact with rocks, stones, debris or other types of objects.
  • Only Specific Vessels Can Fall Dry – Only vessels with a particular hull structure that are designed to fall dry may rest aground. They are typically designed with a flat bottom hull, instead of round bottom or vee bottom hull designs. 

NAABSA Ports and Berths

There are a number of ports that have a wide tidal range, whereby vessels are prone to sit aground when berthed. NAABSA ports or berths are typically found in certain parts of South America (Brazil, Argentina and Paraguay) and Europe (France and the UK). 

NAABSA Ship Operator’s Perspective 

When calling NAABSA ports, there are important aspects that need to be taken into consideration to ensure that best practices are adopted. Here is a general list that ship operators are able to follow: 

  1. Navigational charts should always be up to date at all times.
  2. It is highly recommended to know important details about the port of call even if visited on many occasions.
  3. The ship’s structural integrity, design and requirements should also be known well in advance and accounted for when planning for the voyage. 
  4. Be guided by harbor authorities and pilot boats to know more about the seabed of the assigned berthing area.
  5. Check and ensure that port facilities specific to loading and unloading are always working.
  6. Ensure that latest tidal information is tracked and that the information is verified by local authorities.
  7. Communicate openly and transparently with the shipowner on your requirements and if you require to call a NAABSA port.

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Gerrit Poel

Co-Founder & Writer
at freightcourse

About the Author

Gerrit is a certified international supply chain management professional with 16 years of industry experience, having worked for one of the largest global freight forwarders.

As the co-founder of freightcourse, he’s committed to his passion for serving as a source of education and information on various supply chain topics.