Written Records, AWM54 741/5/9 PART 2 - [Patrols - Reconnaissance:] Report on Northern Territory Special Reconnaissance Unit, by Sqn Ldr D F Thomson RAAF [Report minus maps] - Part 21

SECRET   13. 

APPENDIX IV.

A.K Aroetta

Caledon Bay 

Arnhem Land

Date: August 11th 1942

FOR: ADVANCED HEADQUARTERS, NORTHERN TERRITORY  FORCE 

FROM: O.C. SPECIAL RECONNAISSANCE UNIT.

Report on Completion of  Overland Journey Borroloola and  reconnoitering of Macarthur River Mouth and Estuary  

Following upon my signal by W/T on arrival at Borroloola

of July 25th AI/55. I have to report that I arrived at the 

MacArthur River on that date that I rejoined the Aroetta two days later 

having lightered the stores which I took overland to the McArthur 

River. In the meantime

2.  The object of this journey was to carry out a general 

reconnaissance of the area between the Roper River and the McArthur 

as laid down in my Operational  Instruction No. 13 of April 5th. 1942 

section 3, para. B.  The reports available at various stations on the 

Roper River and the Mataranka concerning the road through Hodgson Downs 

and Nutwood Downs Stations to Tanumbirini [[D.W?]] Station were conflicting. 

For this reason a loaded vehicle.  a four wheel drive  3 ton 

truck carrying four tons of stores, was employed in order to demonstrate 

the degree to which the track could be used by transports and convoys.  

3.  Except for the area of about [[33?]] miles between Bella Glen 

Creek , a tributary of the  Hodgson River, some 15 miles from Hodgson 

Downs Station, and Nutwood Downs, where the country is excessively 

rough, and intersected with numerous steep creeks, with much stone 

outcropping, the road between the Roper River  and the McArthur is all 

easily negotiated by any A.F.V.s and there is no doubt that military 

convoys could be taken through this country at high speed in emergency.  

The wear and tear on all vehicles would be high and the fuel consumption 

would be greatly increased.  However, there is no doubt that there are 

more easily negotiated approaches to the Ls of [[C?]. But the cross 

country route could be taken if necessity arose.

In the wet season, however the country would be impassable 

to all heavy vehicles and would offer excellent opportunities for 

any guerrilla troops accustomed to living in the country, its vulnerability 

is great.

4.   Owing to a broken strut axle which was sustained close to 

Hodgson Downs Station, a delay of ten days in my arrival at 

Borroloola resulted, but actual travelling time was short and much 

useful information was obtained.  A reconnaissance of the road with 

notes on the nature of the surface, the water and the speeds which 

could be attained are being incorporated in a 

report in preparation.  This will be forwarded by safe hand in the next 

outwards mail.

5.   Since leaving Borroloola,  the unit has been fully engaged on the 

programs set out in my Itinerary submitted early in July 

(dated July 3rd).

6.   Visits were made to Vanderlin Island, Maria Island, Groote 

Eylandt and Caledon Bay, and an O.P. was established in the last 

mentioned area.

7.  The vessel is leaving Caledon Bay for Groote Eylandt on 

the night of August 12/13 and will return to Caledon Bay about the 

17th of the month.  Subsequently, it is proposed to continue with the 

programs out in the communication of July 3rd.

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14 

APPENDIX IV

8. A reconnaissance of the mouth and estuarine reaches 

of the McArthur River was carried out by Lieut. Palmer and the crew 

of the Aroetta, during my absence on the overland journey, and 

this report with a sketch map, is forwarded herewith.  The reconnaissance 

report of the overland route will be forwarded later.

(Sgd, )DONALD,. F. THOMSON

Squadron Leader  R.A.A.F.

O.C. Special Recce Unit.

A copy of the Operational Instruction No.5 covering the ensuring 

voyage to Groote Eylandt is attached hereto.

SECRET 

15 

APPENDIX IV

RECONNAISSANCE REPORT ROPER RIVER & SOUTH BANK FROM MOUTH TO MOUNT ROPER

REF: MAP ENLARGEMENT SHEET [[13-5?]] AERONAUTICAL MAP SCALE [[7.85?]] Miles to 1 Inch

Part (1)

RIVER.  The Roper River from the mouth to Mount Roper is 

clear of all obstacles for the navigation of craft with a 

depth of six feet at all tides. Vessels drawing water up 

to ten feet with local knowledge and high tides would have 

no difficulties in ascending the river as far as Mount Roper 

where a sand bar exists and is only navigable at high tides.

The banks of the river on the south side are low and 

in all places , except where the mangroves line the bank, no difficulty would be anticipated in landing A.F.V. and M.T.

Part (2)

NATURE OF THE COUNTRY. The foreshore from the south of 

the river to Childers Creek, distance approx five miles, is 

fringed with mangroves varying in width from fifty to a 

hundred yards, inland from this fringe of mangroves there 

are low sandy plains and salt pans for a distance of one and 

a half miles when the land gives way to low ridges generally of 

sandy gravel with outcrops of stone on the higher hills.

The hills and ridges are covered with a dense 

growth of stunted timber, such as  Acacia, Beefwood, Blackwood, 

Gutta-percha and Quinine bush.

It would not be possible for A.F.V. or  M.T. to operate 

in these scrubby hills without a excellent knowledge of the 

country.

The more typical stringy-bark and ironwood are absent. 

Fine alluvial plains covered with a course grass  from the 

banks on the south side of the river , except in some places 

where mud flats and salt-pans with mangroves extend to the 

waters edge.

These mud-flats and grass plains become inaccessible 

after a few inches of rain have fallen, but during the dry 

season they could be used as landing grounds for air-craft 

and would present no obstacle to A.F.V. or M.T. 

WATER. The entire area east of Mount Roper, to the river 

mouth bordering the river, leaks permanent water at the present 

time, although the dry has only just commenced many of 

the lagoons have became dry and others so brackish as to be 

undrinkable.

A well is situated at No: 1 Camp, due south of the 

landing approx 2 miles distance, water was found at a depth 

of 18 feet.

At No: 2 Camp there is another well, distant [[2.8?]] miles 

from the landing in a N.S.W. direction, although this was 

taken down another five feet no water was found. Local natives 

of this area state that owing to the lack of rain during the last 

monsoon this year the well at No: 1 Camp will become dry before

 the end of the B:N season.

ROADS. There is a wagon track and several natives pads from 

Mount Roper to No: 2 Camp, there is also a motor track ( in 

the dry season from Mount Roper to a stock yard and lagoon 

about 8 miles south of No: 1 camp. A civilian truck has been 

driven from Roper Bar Police Station to the south of the Towns 

River. 18 miles south of the Roper River Mouth.

GAME.  Some game is to found in this area though not 

abundant, and although traces of cattle were about no cattle 

were seen east of No: 2 Camp.

/ General.

SECRET 

16

APPENDIX IV

GENERAL. There are no serous obstacles on the South Bank 

of the Roper River from Mount Roper to the mouth for A.F.V. or M.T. 

provided they kept close to the banks of the River and Dry 

weather conditions prevail.

The only obstacle could be 2 or 3 inches of rain 

which would render the whole area a quagmire, or lack 

of permanent water.

28th. April 1942

Lieutenant A.B. Palmer (Signed)

Special Reconnaissance Unit 

SECRET 

17 

APPENDIX IV

REPORT ON RECONNAISSANCE OF MCARTHUR RIVER

Reference. Sketch Map, McArthur River, Carrington & Batten Creek

Scale X Inch - 1000 Yards

INTRODUCTION

On the 7th July 1942, the Aroetta proceeded from the Roper River 

to the McArthur River via Maria Island and the Pellew Group.

Maria Island

Maria Island lies 15 miles in an Easterly direction off the mouth 

of the Roper River.  There is an excellent anchorage and haven for 

small vessels (Drawing 6-10 feet of water) in Eagle Bay on the West 

side of the Island. In spite of the excessively dry season this 

year, water was still abundant in native wells close to the beach. 

Fish and shell-fish were plentiful but other game was lacking on the 

island. Kangaroo's and wallabies appeared to be completely absent.

PART (I)

MCARTHUR RIVER

After passing through the Pellew Group the approach to the McArthur 

River is marked by an extensive area of shallow water which at this 

season (S.E.) is so dirty and discoloured as to make navigation 

except with the constant use of the lead line a difficult matter.

The minimum depth of the water met with on the bar was 9 feet at 

high water. The rough stakes at present used as beacons to mark the 

entrance channel were found to be unreliable and even with the employment

of a local native with a good knowledge of the entrance, the 

greatest care had to be exercised in taking the Aroetta which was 

drawing 3 feet of water into the river.

The McArthur is navigable as far as Borroloola for vessels drawing 

only 5 feet of water but under specially favourable conditions it 

might be possible for a vessel with 7 feet draught to proceed up 

stream for the same distance. 

The Aroetta was taken for a distance of 18 miles up the river during 

which two shallows were encountered, one of which the ship was just 

able to navigate at high water. It was not deemed advisable to 

attempt to take the ship further up stream without a preliminary 

survey of the river. On the 10th and 15th of July 1942 the ships 

launch was taken up as far as Borroloola.

Part (II)

Description of the River

After the outer bar was passed an average depth of 10 feet of water 

was found until a point 1.5 miles from the sea. Here a sand bar with 

only 8 feet of water was found and the deepest channel through this 

bar was found to be close to the west bank of the river. Deep water 

was found to continue after this bar was passed until Anchor Island 

was reached, here a sand bar extending from the Island to the East 

bank was found to have no more than 7 foot 6inches of water.  As 

the tide was falling the vessel was anchored close to the East bank 

in a depth of 8 feet. At low tide soundings were taken on the bar and 

the most water found was 4 feet 6 inches.  As it was not deemed advisable 

to take the vessel over this bank without a preliminary survey of the river the ships launch was taken up to as far a Borroloola on 

the 10th July 1942.

It was found that the river offered no serious obstacles to the 

navigation of the Aroetta for a distance of 12 miles until the 

junction of a river to the westward locally known as the Carrington 

was reached. Here there were a number of sand bars and shallows 

and although the deep channel was clearly marked with rough beacons 

the most water that could be found in the channel at high water was 

6 feet [[?]] inches.

/on

SECRET 

18

APPENDIX IV.

On the 11th July 1942 at the top of high water the Aroetta was 

taken over the bar at Anchor Island and proceeded to a position half 

a mile to the N.E. of the junction of the Carrington River and 

anchored close into the bank of Kangaroo Island in 18 feet of water. 

On the 15th of July 1942 the ships launch was again taken up the 

river to Borroloola and the following observations were made. After 

Kangaroo Island was passed the river  trends to the south for a distance of 

3.8 miles no difficulties or obstructions were encountered until 

BLACK ROCK LANDING was reached. Here an outcrop of large rocks narrow 

down the channel and although the deepest channel was marked by beacons 

the most water  found was 6 feet [[8?]] inches; the channel here was rendered 

more difficult on account of the string ebb and flood currents. On 

enquiries being made from local natives it was learned that vessels 

carrying cargo for Borroloola were in the habit of unloading at this 

landing and transporting the stores overland by M.T. over a rough track 

a distance 24 miles . It was found out that on one occasion a 

vessel belonging to a local trading company owing to a delay in unloading 

cargo missed the spring tide and was compelled to wait for the next 

spring before she was able to navigate the shallows at Kangaroo Island. 

This vessel had a draught of 8 feet. From BLACK ROCK LANDING until 

BLACKFELLOW CROSSSING is reached the river trends in a S.W. direction 

for a distance of 1.3 miles and although clear of obstructions to 

navigation the depth of water was seldom found to exceed 7 feet and 

the average depth was 6 feet. At BLACKFELLOW CROSSING the width of 

the channel is again narrowed by outcrops of big boulders and the 

greatest depth of water found in the channel was 5 feet, here again 

the deepest channel was clearly marked  with rough beacons.  From 

BLACKFELLOW CROSSINGS to BORROLOOLA the distance is 10.5 miles and 

the river becomes very narrow after passing the crossing and in several 

places is barely 100 yds. wide and seldom depths of more than 5 feet 

could be found.

Many shallows and sand bars exist, some of which are clearly beaconed 

but many are not. The river was found to be too brackish to drink, 

even as far inland as Borroloola. Local residents sate that this is 

due to the exceptionally dry season this year.

PART (III)

CARINGTON RIVER (Locally known)

The Carrington River, see above, branches off from the McArthur River 

12 Miles from the sea separating off a large island known as Kangaroo 

Island. This River runs in a N.W.E direction. It is twelve miles long 

and enters the sea 8 miles to the N.W.  of the McArthur River entrance.

DESCRIPTION

On the 22nd. July 1942, a traverse was made to the mouth and the 

following data was noted... Owing to the numerous sand bars which 

occur along its entire length and also to the extensive mud flats which 

mark its mouth, it would be impossible for craft  drawing more than 

3 feet of water to navigate this stream.  The basks of the river are low 

and densely lined with mangroves, especially at the mouth.

East Bank. At 2.7 miles from the mouth of a shallow salt water creek 

branches off in an Easterly direction.  This shallow creek enters 

into the McArthur River 1.3 miles approx from the mouth.  The Island 

thus formed is unnamed.  It is very low being largely 3 feet above the 

high water level of the river, is composed of salt pans and intersected 

with numerous salt water creeks mainly lined with mangroves on both 

banks.  At 3.5 miles approx a second salt water creek branches off in 

an Easterly direction. This connects with the McArthur River at the point 

2.7 miles from the sea. This Island is also unnamed and is identical 

with the island to the North.  On the South side of this creek is 

Kangaroo Island, it is much larger and higher than the two other Islands 

and it lightly covered with timber and grass.

A fresh water lagoon was formed on the N.W. side of Kangaroo Island, 

situated 400 yds, from the East bank of the Carrington River, and 1800 

yds.. from the South West end of Kangaroo Island. The S.W. side of the 

/ Island 

SECRET 

19 

APPENDIX IV

Island is much higher than the N.E. side, being nearly twenty feet 

above the high water mark of the river.

West Bank.  On the N.W. bank of the Carrington River the shores are 

lined with dense mangroves from the south to a salt water arm, which runs 

in a westerly direction approx.3.8 miles from the mouth of the river.  

After this creek is passed the fringe of mangroves become less dense and 

extensive plains lightly timbered run from the bank of the river in a 

south westerly direction for approx 4 miles until a granite ridge is 

encountered, when the grass becomes scarce and the timber and scrub more 

dense.

PART (IV)

BATTEN CREEK

Batten creek joins the Carrington River about 500 yds., after the 

Carrington branches off from the McArthur River at Kangaroo Island. 

On the 17th July 1942, the ships launch was taken approximately 9-10 

miles up this creek. It was found to be shallow with many sand bars 

and shoals patches at low water. Great difficultly was experienced in 

navigating the launch in certain places, in spite of the fact the launch 

was drawing only 12 inches of water.

The banks of the creek are marginally fringed with mangroves which on the 

south side give way to open plain and grass country lightly timbered. On 

the north side it is mostly timbered with trees and scrub with many 

outcrops of granite.

PART (V)

RECONNAISSANCE OF BATTEN CREEK AREA.

On July 18th, 1942, a traverse of the area between Batten Creek and 

McArthur River was made. From a point 300 yds. on the south bank of 

Batten Creek from where it joins the Carrington River, a bearing North 

71 degs (True) 6.5 miles was covered on the traverse until the south 

bank of Batten Creek was reached.  After the light mangrove fringe on

the bank was crossed, for 400 yards  the country was grass plain country 

which was covered with light timber, the timber getting thinner until a 

freshwater lagoon was found situated 250 yards  from the south bank of 

Batten Creek.  With the exception of a small lagoon  on Kangaroo Island 

and a native well on the North bank of the McArthur River at BLACKFELLOW CROSSING this was the only water encountered in the whole of the lower 

reaches of the McArthur River.  The water was good but had already dried 

up to half its normal size owing to the prevailing dry conditions.  

From the lagoon an extensive grass plain was crossed approx 2.5 miles 

in an east and west direction and continuing nearly to the bank of the 

McArthur River in a Southerly direction for 5 miles.  After crossing this 

plain light timber and scrub was encountered which extended to the banks 

of the Batten Creek. At this point the south bank of the Creek sloped 

gently to the water while on the north side of the bank was 10-15 feet 

high and densely covered with timber and scrub.  The depth of Batten 

Creek at this point was 3-5 feet  deep and about 30 yards wide.  From 

this point on Batten Creek [[on a?]]  true South bearing a point approx 1 mile 

North of BLACKFELLOW CROSSING. When the McArthur River was reached, 

the distance was approx. 6.3 miles. The country travelled was was grass land 

lightly covered with timber [[bafing?]] out into many gullies as the banks of the McArthur River were [[?]] the height of this plain was estimated 

at 25 feet above the high water level of the river.

PART (VI)

GAME AND RESOURCES

 Game abounds over the whole of this area covered in this reconnaissance, 

wallabies are present in incredible umbers on the banks of the rivers 

and the surrounding country. Cattle were numerous on both banks of the 

McArthur River and Batten Creek. Ducks and Geese were plentiful on the

lagoons at Batten Creek and Kangaroo Island. The river also teams with 

fish, so that no difficulty would be experienced by any guerilla party 

living on the country.  The only trouble would be the lack of fresh water 

as the limited supply found is liable to become too brackish to be 

palatable as the end of the dry season approaches.

Lieutenant A.M. Palmer

Special Reconnaissance Unit - Northern Territory 

Dated 11th August 1942

APPENDIX V. MAPS

The following maps covering special aspects of he work and areas of 

intensive work of the Special Reconnaissance Unit are attached:

1. Map of Arnhem Land showing routes on Sea and Land 
   Patrols carried out by Special Reconnaissance Unit in 1942 with 
   Key tracks attached.
2.  Map of Arnhem Land showing principal sites occupied by 
   Malay voyagers who came from Macassar in the Celebes prior to the 
   days of Mathew Flinders. The principal bays and rivers which afford 
   shelter for small ships of flying boats are also indicated, with 
   notes on the chief features of these.
3.  Map of the Roper River showing the approaches covered by O.P. 
   at Mount Moore or Gulnare Bluff. 
4. Rough sketch maps of Jensen Bat, Wessel Island
5. Traverse sketch of McArthur River Estuary.
6. Rough Survey sketch of Port Bradshaw, Gulf of Carpentaria.

APPENDIX VI 

LOG OF A.K. AROETTA from December 1st 1941 to April 12th 
1943

APPENDIX

DECK LOG OF THE DEFENCE KETCH "AROETTA"

OF

SPECIAL RECONNAISSANCE UNIT

On Coastal Patrol and Reconnaissance for Flank

Protection - Darwin Area

 

COMMANDED BY 

D.F. THOMSON Squadron Leader  RAAF (Seconded)

LOG KEPT BY

SGT. (Later Lieutenant ) A.K. PALMER 2 I/c  

1941 - 1942

Date	Courses	Wind	Time	Remarks
1/12/41		E to NE Light in AM Fresh in PM  Sky [[c?]]		Work on installing main engines and auxiliaries. Also installation of  oil and fuel pipes. Painting all new  timber with red lead. Two carpenters  who were employed failed to turn up  for work. Reported matter to Interior.  Main standing rigging completed.  Timbering in of fuel tanks in progress  and plumber installing piping.
2/12/41		NE to N Light and variable. Sky O.C.		Main engines correctly aligned and  fastened down.  Engineers on fuel and  air piping. Two Carpenters reported  for work at 1300 hrs. Commenced work  on after cabin and chart house.  Shipwrights finished scuttles and  engine room hatches. Crew oiling and varnishing main cabin; also painting  16 foot launch.
3/12/41		N to NW. Light airs in the AM. Heavy squalls in PM.  Sky O.C.R.		Engineers working on main engines, air and oil lines. Shipwright commenced  repairing 12 foot dingey which is in  very bad condition.   Crew painting all new timber work and  also launch and main cabin.   Installing water tanks and service  tank.  Carpenters on mizzen mast step  and chart house. Plumber on lavatory fittings.  Wire received stating crew arriving 5th Dec. 41. Definite reply re  refrigerator.
4/12/41		N to NE. Light airs in the AM. Heavy rains in PM.  Sky C.		Engineers on piping and exhaust  fittings. One carpenter on after cabin  and chart house. One carpenter on  awing stanchions. Shipwrights  repairing 12 foot dinghey. Crew painting launch and varnishing main cabin.  Notified Interior that natives from  Palm Island were terminating contract tomorrow and to be returned to the Settlement.  Transport to pick up Sgt. Elkington and crew arranged for.
5/12/41		N to NE. Fresh in PM. Sky B.C.		Sgt. Elkington and crew arrived 0625.  Natives returned to Palm Island.  Engineers on piping of main engines. Carpenters on after cabin, chart house  and awning stanchions. Crew overhauling all blocks and painting same.  Drew blankets for Native Crew. Shipwrights on 12 foot dinghey. 16 foot launch painted inside and out ready for replacing engine.