Dawson Harbour 45°44’.10N 005°57’.79W
Southern Peninsula CHARTS RYA 3, 4. Standard Port COLVILLE ( ) Times
High Water
0100 1300
0700 1900
4.8 Height (metres)
Low Water MHWS MHWN MLWN MLWS 0100 0700 1300 1900
3.9
Differences Dawson Harbour -0038 -0014
-0030 -0006 +2.8 +1.7 1.4 +1.0 0.5 +0.5
DESCRIPTION. Excellent shelter within this well-protected harbour which has three granite outcrops (The Rocques) positioned at the entrance acting as natural breakwaters. The entrance and main channels are accessible at all states of tide. Dawson Harbour has managed to keep its unspoilt charm and, although there are some facilities for visiting yachts and motor boats, these are somewhat limited given the size of the harbour. With careful pilotage and sufficient rise of tide the various reaches in the harbour can be explored. There are AB at Old Dawson and North Mattville. Berthing at South Mattville is exclusively reserved for FV. Secure anchorage, in sand, in East Dawson Creek.
APPROACH WAYPOINT. 45°46’.92N 005°57’.24W.
PILOTAGE NOTES. The approach to the entrance is straightforward and clear of dangers. The Outer Rocque Lt Ho is conspic day and night. The entrance is protected by three rocky islands, the Inner, Middle and Outer Rocques. The recommended passage is through the ‘Flanker Channel’ which passes between Middle and Outer Rocque (least depth 3.3m). The conspic radio mast on Mattville Down should be used to provide a leading bearing until the hotel transit can be identified. At the heads, the eastern side of the entrance should be favoured, as a shallow sand spit extends from Dawson Head. Once through the heads the harbour is unlit and has only a few beacons to aid pilotage. Night entry is not recommended without local knowledge.
TIDAL STREAMS AND HEIGHTS. The harbour has a large tidal range (6.6m at springs) and the spring rate can reach over 4kn through the various Rocque channels and the heads. At certain states of the tide, vessels navigating the Flanker Channel and the harbour approaches may be subjected to a strong lateral set and it is therefore imperative that transits are used and held. The tidal streams within the harbour are variable in both direction and rate but generally tail off near the end of the various creeks.
TIDAL HEIGHT ANOMALY IN DAWSON BAY. Two factors contribute to an unusually large tidal range in Dawson Bay. Initially the SE-going flood builds up in the narrow Neptune Channel, between Slade Island and Beauty Point. This creates a restriction that increases the sea height locally and causes the strong tidal stream through the races. Secondly, a proportion of the SE stream, confined by the narrows of the Neptune Channel, turns back on itself, creating the reverse NW-going eddy. This further augments the tide-raising effect within the bay. Note: The 5m and 2m charted contours around the Rocques and within the harbour itself are approximated, and should be used with caution.
LIGHTS AND MARKS. The distinctive Outer Rocque Lt Ho [Fl(2)10s30m12M] (W twr R spiral stripe) is situated on the northern end of the Island. A further major Lt Ho on Old Chapel Head [Oc(2)8s45m15M] (W twr) is a mere 2.6M from the Outer Rocque Lt Ho. There are no lights within the hbr. Four cardinal posts indicate the extremities of the primary rock ledges.
VHF RADIO. None.
FACILITIES. Old Dawson – FW, Gas, CH, Bar. North Mattville – FW, Bar.
H.W.Hts at Secondary Port 0
2
4
6
8
10
-7h -6h -5h -4h -3h -2h -1h
L.W. +1h +2h +3h +4h +5h +6h +7h +8h
Mean level
Range at Colville Sp
OLD DAWSON 0
L.W.Hts.m 86 2 4 6 8 10
Mid Np
4.3m 3.4m 2.5m
1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0
Factor
CHART DATUM
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100
