What is a proforma disbursement account (DA)?

A proforma DA is the ship agent's advance estimate of all costs a vessel will incur at a port — dues, pilotage, towage, mooring, and agency fees. The owner or charterer funds it before arrival, and a final DA reconciles actual costs afterward.

Why are port charges scaled on gross tonnage?

Gross tonnage (GT) is a dimensionless measure of a ship's total internal volume and is the standard basis most ports use for dues. Larger vessels occupy more berth and infrastructure, so charging per GT spreads port costs fairly across ship sizes.

Why is pilotage counted twice?

A port call usually needs a pilot inbound to bring the ship to the berth and another outbound to take her back to the pilot station, so this tool counts two pilotage movements by default. Some ports also charge per nautical mile of channel, which you can fold into the per-movement rate.

How is towage estimated?

Towage is charged per tug per movement. The tool multiplies the per-tug rate by the number of tugs and by two movements (berthing and unberthing). A large tanker may need three or four tugs, while a small coaster may need none.

Does this cover every DA line item?

No. It estimates the largest variable items — dues, pilotage, towage, and agency fee. A full DA also includes mooring gangs, garbage and sludge disposal, fresh water, light dues, and customs and immigration fees, which you should add for a complete proforma.

Ship Port Call Cost Estimator

Before a ship arrives at a port, the agent issues a proforma disbursement account estimating what the call will cost. This tool builds an indicative proforma by scaling the main charges — port dues, pilotage, towage, and agency fee — from the vessel’s gross tonnage and a handful of tariff inputs.

How it works

Port dues are charged per unit of gross tonnage. Pilotage and towage are charged per movement, and a standard call has two movements (inbound to berth, outbound to sea). The agency fee is a fixed amount for the call:

port_dues  = gt × dues_rate_per_gt
pilotage   = pilotage_per_movement × 2
towage     = towage_per_tug × tug_count × 2
total      = port_dues + pilotage + towage + agency_fee

The two-movement assumption reflects that a vessel is normally piloted and towed both when berthing on arrival and when unberthing on departure.

Example and tips

A 30,000 GT bulk carrier at a dues rate of 0.30 per GT incurs 9,000 in port dues. With pilotage at 1,200 per movement (2,400 for the call), two tugs at 800 each over two movements (3,200 towage), and a 1,500 agency fee, the proforma totals about 16,100. Remember this is the variable core only: add mooring gangs, garbage and sludge disposal, fresh water, light dues, and customs and immigration to reach a complete DA. Always confirm the actual port tariff, as dues bases and minimums vary widely between ports.