LNTM 29-26 – Hovercraft Survey Works – 8th and 9th November 2026

All Mariners are advised:

Core sample surveys are scheduled to take place on the mudflats on Sunday 8 and Monday 9 November. The surveys will commence at Dittisham and progress upstream as far as Totnes. Access to the mudflats will be undertaken using a 5m hovercraft (pictured below).

The hovercraft operators hold a permit, approved by the Harbour Master, authorising them to exceed the six knot speed limit. However, the hovercraft will operate primarily over exposed intertidal mud wherever practicable and is unlikely to exceed 15 knots when travelling over these surfaces.

The hovercraft is expected to use the navigable channel only when necessary, primarily when crossing from one side of the river to the other. On these occasions, it will travel at a maximum speed of approximately 12 knots. This is the minimum speed required to maintain planing and is also the hovercraft’s quietest and most manoeuvrable operating speed, generating virtually no wash.

The engines will be stopped upon arrival at each sample site.

The operators have been instructed to give other river users as wide a berth as practicable. This will generally be achieved by operating over the mudflats or in very shallow water along the edges of the navigable channel.

When required the hovercraft will operate without lift power and will be manoeuvred using its thrust engine only, known as boating mode. In this mode, its maximum speed is approximately 3 knots.

Dart Harbour has instructed the operators to remain in boating mode whenever they are within mooring fields and further upstream, where tight bends can restrict visibility and increase the risk of encountering other vessels.

Issued 4th November 2026

J Handley – Assistant Harbour Master