Up the River Blackwater - Osea to Maldon

Up the River Blackwater - Osea to Maldon - A guide by the RYA for the River Blackwater

Competitors in the Annual Maldon Mud Race

The River Blackwater

The upper reaches of the River Blackwaterharbours a secret or two. Whilst there are some great little creeks andand intruguing harbours, there is also an Island that was a top secretnaval base and Maldon, which made the area famous for its Sea Salt.

TheBlackwater is wide and deep as it runs past Mersea Island and Tolesburyto its North and Bradwell to the South. The river narrows as itapproaches Osea Island and the Marconi Sailing Club, which is where ourjourney starts.

Moorings on the southern edge of the river near Marconi SC.

A shoreline dotted with masts and a series of mooring trots denotesthe Southern side of the river as we pass the Stone and then MarconiSailing Club. A Green lateral mark (No1) to the North indicates thechannel leading off Goldhanger Creek.

Marconi Sailing Club and the Marconi red lateral mark (chart point 1)

Osea Island

Deep water passes to the South of Osea Island. A green lateralmark (No3) keeps you clear of the drying bank called �The Doctor� onOsea�s SW side and marks theSW extent of the popular Barnacle anchorage that nestles off Osea�sSouth East corner. Osea has been inhabited for approximately 5000 years.In more recent times, it was a Victorian alcoholic rehabilitationcentre and, rumour has it, local sheep farmers who crossed the tidalcauseway had a roaring trade smuggling bottles of �medicine� to patientsby hidding the bottles in the fleece.

The Admiralltyrequisitioned Osea during the 1st World War for use as a top-secretnaval base. �S.S Osea�, was so secret that many locals had no idea thatover 1000 sailors were based there. Today the island is privately ownedoffering holdiay accommodation.

Barnacle anchorage to the South East of Osea Island (chart point 2)

Lawling Creek

The start of Lawling Creek is opposite to the Southern tip ofOsea Island. Red lateral mark (No2) indicates the start of the channelwhich courses South Westerly towards Blackwater Marina. The Marina wascreated during the 2nd World War, the government financed the buildingof a boatyard in Mayland to allow the Cardnell brothers, Tom &George to build much needed Motor Torpedo and Gun Boats.

Distinctive house and remains of the landing pier on the Southern tip of Osea Island (chart point 3)

Backto the Blackwater and Osea Island, as you pass Green lateral mark (No3)the channel turns North West until the Northern bank starts to showitself and moorings start to increase once again. Red lateral mark (No8)indicates a sharp turning point whereby the channel sweeps around tothe South West becoming Colliers Reach. The Northern bank is home toBlackwater Sailing Club and the area is very busy at the weekends withdinghy racing.

Blackwater Sailing Club on the Northern Bank as the channel turns SSW into Colliers Reach. (chart point 4)

Heybridge Basin

A couple of cables into Collier Reach brings you to CRS MarineBoatyard which has the odd mooring by arrangement and where the oldchandlery has been converted into a tea room managed by Wilkin &Sons of Tiptree who are famous for their jams.

The lock, buildings andtraffic signals at Heybridge Basin come clearly into view. The basin isthe start of the Chelmer & Blackwater Navigation which is a 13 milecanal connecting Chelmsford to the sea. The project commenced in 1793and was a main supply artery until it fell into disuse in the 1970�s.It�s trade now are the multitudes of pleasure craft and moororing isavailable to visiting craft within the basin.

Normally lockingout occurs first and when the traffic light is green you can make yourapproach. Leave the lock approach buoy close to starboard and headtowards the withies. Call the lockeeper on Channel 80 for advice.

Entering the lock at Heybridge, the traffic light on green can be seen on the shore to the left of the withies (chart point 5)

TheSea Lock is operated 1 hour before HW to 30 minutes after HW. Duringthe summer months (April to September) the lock operates on all daylightHigh Waters. Due to it�s popularity during the summer months it it isalways advisable to book a berth in the Heybridge Basin, especially atweekends when yacht club rallies often visit the Basin.

The Heybridge lock & basin.


Passing Heybridge,Colliers Reach continues to the South South West, turning to the NorthWest and hugging the Northern Bank. The channel continues to hug theNorthern bank until you are roughly North of the Maldon Pier head, nearthe Maldon Sailing club, at which point the channel crosses to theSouthern bank and stays there all the way to Maldon.

Pier head at Maldon (chart point 6)

The first settlers to thedistrict came in the Bronze Age and settled to the north of what is nowthe town of Maldon. Salt marshes proved popular for salt harvesting asshown in the 1086 Doomsday survey where 46 salt pans were recorded inthe Maldon area.

Hythe Quay at Maldon takes it�s name from theSaxon word Hythe meaning landing place and typically a multitude ofSailing Barges are seen moored up. Maldon sailing barges traded up anddown the east coast and supplied much of London with agriculturalproducts. Today, it�s a barge and traditional boat mecca and many bargesstill trade but now mainly with human cargo - for charter and rivertrips.

It is best to contact Maldon tourist Office foravailablity on the Quay, but if you are staying you should be capable oftaking the ground.

Maldon Quay lined with barges (chart point 7)

Maldon is apopular tourist destination by land and worthy of a visit by sea as longas you keep a keen eye on the tide to avoid becoming stuck in the mudof which there is plenty. So much in fact that Maldon now hosts anannual fundraising mud race with competitors running through the mudfrom Maldon across the other side of the river and back again.

Fact file

Tollesbury Marina www.tollesbury-marina.co.uk
Bradwell Marina www.bradwellmarina.com
Blackwater Marina www.blackwater-marina.co.uk
Goldhanger Sailing Club www.goldhangersailingclub.org.uk
Marconi Sailing Club www.marconi-sc.org.uk
Blackwater Sailing Club www.blackwatersailingclub.org.uk

Tollesbury Marina
Ch 80 or 37 phone 01621 869202
Bradwell Marina
Ch 80 or 37 phone 01621 776235
Blackwater Marina Ch 37 phone 01621 740264
Heybridge Basin Ch 80 phone 01621 853506
CRS Marine Phone 01621 854684
Hythe Quay
(Maldon Tourist office)
Phone 01621 856503


Walton on the Naze
3.8m MHWS 4.2
MLWS 0.4
Neap 2.3m MHWN 3.4
MLWN 1.1

Osea Island�� Range Heights
Spring 4.9m MHWS 5.3
MLWS 0.4
Neap 3.1m MHWN 4.3 MLWN 1.2

Maldon Range Heights
MHWS 2.9
MLWS dries
MHWN 2.3 MLWN�dries


Barnacle Anchorage South East corner of Osea Island
Avoid anchoring on the Oyster beds


Imray Y17
Admiralty SC5607


Chart Y17 is reproduced with the kind permission of Imray.www.imray.com

Chart copyright UKHO. www.ukho.gov.uk

Words &pictures By Simon & Vicky Jinks, SeaRegs www.searegs.co.uk

� Crown Copyright and/or database rights. Reproduced bypermission of the Controller of Her Majesty�s Stationery Office and theUK Hydrographic Office (www.ukho.gov.uk).

This material is not for resale, redistribution or copying.
Not to be used for navigation.