A 1,300-tonne dredger aborted its entry into Littlehampton Harbour due to 'inconsiderate seamanship' from smaller vessels, the harbour board has said.
On Saturday, August 3, the Arco Dee - a 68-metre-long, 14-metre-wide commercial vessel - had dredged 1,200 tonnes of sand from the seabed off the Littlehampton coast.
According to the Littlehampton Harbour Board, at 2pm the harbour was closed so the dredger could enter at high tide - the safest time to do it.
But due to 'a number of vessels still attempting to enter or depart the harbour' ahead of the Arco Dee, including one sailing yacht 'putting herself at significant risk', the manoeuvre was aborted at 2.33pm.
In a statement from Littlehampton Harbour Board, it said: "Poor decisions made by a minority of vessel skippers risked a potentially very serious incident and made the port closure last twice as long as normal.
"Littlehampton Harbour Board would like to thank the majority of vessel skippers to co-operated, kept themselves informed by VHF radio and as a result did not put themselves or any other vessels at risk.
"A number of small vessel skippers have been formally cautioned by the harbour master and further enforcement action is currently pending in some cases."
The harbour board explained that getting larger vessels into the harbour was already a 'challenging business' as the entrance is 31 metres wide at its narrowest point, has a strong tidal stream that pushes boats sideways on approach and is shallow enough that many big ships only have 50cm clearance above the seabed.
At 2pm, harbour master Billy Johnson boarded the Arco Dee and made the standard safety broadcasts over VHF Radio to announce the temporary closure of the harbour.
The planned entry at 2.15pm was delayed by 'a number of vessels still attempting to enter or depart the harbour' ahead of Arco Dee, 'deliberately evading the efforts of harbour staff' who had asked all vessels to return to their moorings.
One sailing yacht made a late entry ahead of the vessel at a slower speed, the harbour board said. Despite direct attempts to contact it on different radio channels, and the Arco Dee's captain sounding ten blasts on its horn, the yacht did not adjust its course.
With the risk of collision imminent and there being a 'significant danger to life', the Arco Dee made a hard turn to the left and a tight figure of eight turn to line up for a second entry.
The confusion meant that other boats took the opportunity to enter or exit the harbour, delaying this attempt.
But despite this, the Arco Dee entered the harbour safely at 2.50pm, 55 minutes after high water, and was safely moored on its berth by 3.15pm.
Littlehampton Harbour Board, as a statutory harbour authority has the power to prosecute for breaches of regulations or special orders by staff.
A person who fails to comply could go to court and be fined up to £2,500, the harbour board said.