Non-Reversible Laytime

What it does

Non-reversible laytime keeps the loading allowance and the discharging allowance in separate accounts. The time used at the load port is assessed against the load allowance, and the time used at the discharge port against the discharge allowance, with no pooling between them. A saving at one port stays at that port and cannot be carried across to cover an overrun at the other end of the voyage.

This is the position that applies whenever the charter does not make laytime reversible, and in many standard forms it is the default. Because each operation stands alone, demurrage can arise at the discharge port even where the load port was completed well within time, since the unused load hours are simply lost rather than added to a common pool the charterer could draw on later.

Commercial effect

Separate accounting works in the owner's favour, because it maximises the occasions on which delay produces demurrage. A charterer cannot lean on efficiency at one end to rescue a slow operation at the other, so any port that overruns its own allowance generates a charge regardless of how the rest of the voyage went, and the owner is paid for delay wherever it occurs.

For the charterer the effect is to remove the cushion that reversibility provides, exposing it to demurrage on the weaker leg of the voyage even when the overall time used was reasonable. The choice between reversible and non-reversible laytime is therefore a direct allocation of delay risk, and it is bargained alongside the length of the allowance and the demurrage and despatch rates.

Owner's perspective

The owner generally favours non-reversible laytime precisely because it prevents the charterer from offsetting a slow port against a fast one. Each allowance is a separate threshold, and crossing either one produces demurrage, so the owner has more opportunities to be compensated for the time the vessel spends beyond the free period at any single port in the rotation.

The owner wants the clause to state clearly that the allowances are separate and that unused time at one port is not transferable to the other. Where the charterer presses for reversibility, the owner treats the concession as part of the wider package, typically expecting something in return such as a shorter total allowance or a firmer freight rate to balance the risk it gives up.

Charterer's perspective

The charterer carries more risk under non-reversible laytime, because a delay at one port cannot be absorbed by speed at the other. It must therefore be confident that each allowance, taken on its own, is adequate for the operation at that port, including the weather, congestion, and shore delays it expects there, since a tight allowance at a slow port is a direct demurrage exposure.

Where the charterer cannot secure reversibility, it focuses on getting each separate allowance right and on building in the exceptions it needs at the more difficult port. It also checks the position against its sale or sub-charter terms, since a non-reversible structure can leave it paying demurrage on one leg with no matching recovery from its counterparties downstream.

Negotiation points

• Whether the charter is genuinely non-reversible or whether reversibility can be secured for the voyage.
• The adequacy of each separate allowance for the specific operation at each port.
• The exceptions applying at the slower or more weather-exposed port, where the risk concentrates.
• How the structure aligns with the charterer's onward sale or sub-charter laytime terms.

Common variations

• Default non-reversible counting, with load and discharge settled independently.
• A longer allowance at one port to reflect its slower equipment or congestion.
• An option for the charterer to elect reversibility within a stated period.
• Averaging as a partial alternative, netting the separate results against each other.