Westhaven Marina Proposed Pile Berth Redevelopment Navigation Safety Report

Capt. Jim Dilley, Master Mariner

Contents INTRODUCTION ...... 3 EXECUTIVE SUMMARY ...... 5 EXISTING SITUATION ...... 5 Western Entrance/Exit ...... 5 Navigation at the entrance ...... 6 Area outside the entrance ...... 7 Other traffic ...... 8 Harbour bridge traffic ...... 8 Race starts ...... 9 Risk assessment ...... 9 Berthing ...... 10 Eastern Entrance/Exit ...... 10 Navigation at the entrance ...... 11 Pile Moorings ...... 12 Marina Fairways and Traffic Hubs ...... 12 PROPOSED SITUATION ...... 14 Construction ...... 14 Marina Berths ...... 15 Closure of Western Entrance ...... 15 Vessels affected ...... 15 Berthing ...... 16 Marina fairways and traffic hubs ...... 16 Oil spills ...... 17 Start box ...... 17 CONCLUSION ...... 18 Recommendations ...... 18

INTRODUCTION

This report discusses potential navigation safety implications that could arise from the construction and subsequent operation of the redevelopment of Westhaven Marina, hereafter referred to as the Application. The Application includes an extension for the western breakwater to connect to the eastern breakwater to provide public open space and parking. The public open space has been designed in conjunction with local iwi. The proposal also includes the conversion of existing pile moorings to pontoon berthage. (see Fig. 1 and the Westhaven Marina Proposed Occupation Area Fig. 2).

Figure 1. Proposed re-development: Breakwater extension Pontoon berths

Figure 2. Westhaven Marina Occupation Area

The term navigation safety refers to the safety of a vessel or vessels interacting with: another vessel or vessels; the seabed; a structure; a natural object, such as rock or the foreshore; or any combination of the above. As such, as soon as one vessel is operating in an area, there will be navigation safety issues. Navigation safety issues may be minimized or reduced to an acceptable level, but cannot be completely resolved if vessels are operating in an area. Navigational Safety Management is the system of criteria, standards and competence that maintain the ability of a vessel or craft to navigate safely in confined waters such as are found in harbour areas. The most recent occupation permit has addressed this matter to an extent by delineation a vessel transit area (refer Fig. 2)

The New Zealand Port and Harbour Safety Code (the Code) was introduced in 2004. The Code brings together a succinct digest of the formal duties and responsibilities of participants in port and harbour safety and a corresponding statement of the specific measures appropriate to their fulfilment. A critical component of the Code is safety management systems based on risk assessment. The Code has been adopted by the Auckland Council and a Code Application Assessment, Risk Assessment and Safety Management System has been developed. The assessments and Safety Management System have been approved by Maritime New Zealand and are under continual review and audit. The Safety Management System sets out how the Auckland Council, through the Harbourmaster, manages the safety of navigation. The risk assessments assist in identifying where possible risk may exist and how control measures may help in the mitigation of a risk. The Auckland Region Risk Assessment

and its annual review (the Risk Assessment) (excluding the operation of shipping to POAL wharves and the operation of RNZN vessels and berths) is undertaken by the Harbourmaster. Navigation safety issues in the Waitemata Harbour are part of this Risk Assessment.

EXECUTIVE SUMMARY

The proposed re-development has built on existing good practice and international standards to provide a practical and effective use of existing space. The increase in the safety of navigation both within the marina, and in the area immediately to the north of the marina, is evident.

The only possible adverse effects are a small time inconvenience to some of the vessels that use the western entrance, and a small percentage increase in traffic volume at the eastern entrance.

Overall, the proposal provides an appreciable increase in the safety of navigation in the area and provides for manageable and accessible berthing of vessels. The possible effects of any construction and ongoing maintenance and dredging work are easily managed in line with current good practice.

I recommend the movement of the Start Box to the east as suggested in the proposal.

EXISTING SITUATION

At present, vessels may enter or leave Westhaven Marina through one of two entrances, the western and eastern entrances (Figs. 3 and 5).

Western Entrance/Exit

The western entrance/exit (hereafter western entrance) is approximately 60 m wide1 (see Fig. 3). On either side of the gap are rock breakwaters, which extend at an angle underwater thus, reducing the effective width of the channel. The wider western breakwater has a gangway for access to marina berths on pier A extending at an angle2 (see Fig. 3). The fairway in the marina adjacent to this entrance is approximately 60 m wide. The entrance is marked by aids to navigation on both sides (lights: Oc.G.5m5M and Oc.R.5m5M). There is a tidal flow during the flood tide through the entrance of approximately 0.2 m/s (0.4 knots).2 Outside the entrance the flood tide flows west and the ebb tide flows east, at approximately 2 knots.3 There is

1 Proposed Westhaven Pile Berth Redevelopment (Stage 1) Design Report. Beca Ltd 5 August 2015, Fig 1. 2 Ibid., p.10. 3 Chart NZ5323

an extreme significant wave height through the western entrance of 0.95 m.4 to the west of the entrance is an area of shallow water (<5 m) marked by a red buoy (see Fig. 4).

The western entrance provides a route for vessels in the marina navigating to, and from, destinations to the west in the upper harbour and the start line for yacht races, which is shorter than using the eastern entrance. Vessels may also use this entrance to navigate to, and from, areas to the east (the Hauraki Gulf). This is likely to be the vessels berthed immediately adjacent to the entrance i.e. only the vessels in the berths of row A and the western pile moorings in the 100 series berths have a shorter distance to travel using this route rather than the eastern entrance. Once outside the western entrance, vessels are restricted to a speed of 5 knots within 200 m of the shore and to 12 knots in the harbour. This speed restriction means that vessels traveling outside the marina are unlikely to reach a point opposite the eastern entrance any faster than vessels travelling in fairways within the marina.

Navigation at the entrance

Vessels departing the marina through the western entrance must alter course in the entrance to avoid the gangway to pier A (see Fig. 3). This line of approach means that departing vessels may not see vessels entering the marina until level with the start of pier A (see Fig. 3). Vessels entering the marina through the western entrance must also alter course in the entrance to avoid the gangway to pier A. Once inside the marina, vessels navigate between pier A on the right and a line of vessels in pile moorings to the left. This line of approach means that vessels entering the marina here may not see vessels departing the marina until level with the start of pier A. In general, the best practice for passing through a narrow channel is to navigate in a straight line. This allows vessels to line up an approach to the entrance with a clear line of sight. Vessels are then able to see other traffic that may be using the entrance and also are able to judge the effect of tide on the vessel before passing through the narrow gap. Being forced to make a course adjustment in a narrow channel introduces more potential for mistakes to be made. In addition, the tidal flow (0.4 knots) and wave heights (0.95 m)1 will at times cause vessels to have difficulty in negotiating this entrance.

4 Ibid.

Figure 3. Western entrance showing passage route in and out on same scale as figure 5.

Area outside the entrance

Vessels departing the marina through the western entrance emerge into an area of the Waitemata Harbour approximately 600 m from the Harbour Bridge and 150 m from the start box for yacht races. The start box is currently situated on the breakwater between rows C and D (see Fig. 4). This area is subject to strong tides flowing perpendicular to vessels departing the entrance (the flood tide flows west and the ebb tide flows east, at approximately 2 knots4).

Figure 4. Race start box area Start box Harbour Bridge precautionary area

Other traffic

Other vessels in this area include vessels transiting under the Auckland Harbour Bridge (Harbour Bridge), including bulk carrier ships navigating to and from Chelsea Wharf, naval vessels navigating to and from Kauri Point Wharf, scheduled ferries navigating to and from West Harbour, Northcote Point, Birkenhead, Hobsonville and Beach Haven, superyachts, charter vessels and various recreational craft; yachts heading toward or positioning at the start line for yacht races (opposite the start box); seaplanes; and various other small commercial and recreational craft that may use the area.

Harbour bridge traffic

In particular, vessels exiting the marina at the western entrance come into conflict with vessels navigating in the vicinity of the Harbour Bridge that may be constrained because of their draft or air draft. Large vessels, such as ships, superyachts and ferries can only pass under the bridge between the two northern-most supports (this corresponds to the highest point of the bridge). This means that large vessels are navigating to approach a gap of approximately 300 m wide (compared with the total bridge span that is approximately 980 m wide).

The centre span of the bridge is 45 m above chart datum. This reduces to 43 m at 76 m either side of centre. Vessels transiting the bridge must have a minimum clearance of 1 m at the 76 m off centre point. If the clearance is less than 3 m Transit NZ must be contacted to ensure there is no staging, hosing, or scaffolding under the centre span. Transits can only be conducted in daylight and all vessels over 80 m in length must have one tug made fast. A precautionary area surrounds the Harbour Bridge in which no vessel may impede the passage of a vessel under pilotage, a warship, a passenger ferry or a vessel over 500 gross tonnes. Shown in magenta on charts NZ5323 (see Fig. 4) and NZ5322. The western entrance is approximately 150 m from the start of the precautionary area (see Fig. 4). Thus, vessels using the western entrance heading west are almost immediately in the precautionary area and in potential conflict with large vessels restricted in their approach to the Harbour Bridge.

Race starts

The site of the start box determines the start line, which is approximately 150 m from the western entrance. Thus, vessels using the western entrance emerge into an area in which yachts are positioning at the start line during yacht races. Racing yachts prior to the race start are usually performing many short manoeuvres in a confined space in an attempt to get to a desired position for the start. This results in many yachts on different, unpredictable courses, which can cause confusion, especially for non-racing vessels, resulting in the potential for collisions.

The start line is approximately 200–300 m from the Harbour Bridge. This results in potential conflict between racing yachts and other vessels navigating in the vicinity of the Harbour Bridge, particularly commercial ships and ferries. In addition, the close proximity of the bridge has resulted in racing yachts colliding with the bridge structure.

Risk assessment

The Auckland Council has a risk assessment matrix for the Auckland region, including the Waitemata Harbour. This matrix assesses the frequency of an incident occurring and the consequence if it were to occur. The Auckland Regional Council’s Annual Risk Assessment Review 20145 for Waitemata ferry operations (Birkenhead to Westhaven Marina) identifies risks, including risks associated with a commercial ferry colliding with a recreational vessel, a recreational vessel colliding with another recreational vessel, a recreational vessel contacting the Harbour Bridge and a collision as the result of a vessel encountering a yacht race.

5 Auckland Regional Council’s Annual Risk Assessment Review 2014.

Berthing

The narrow western entrance creates an increased tidal flow [at flood tide of approximately 0.2 m/s (0.4 knots)].6 This tidal flow can create problems for vessels mooring or berthing in the area. Tidal flows can cause vessels to speed up, slow down or push vessels sideways depending on the speed and direction of the flow. For vessels manoeuvring in a confined space when berthing, external influences such as tide, and also wind, make it difficult to accurately judge the vessel’s relative position and speed, which is needed to be able to place the vessel in the berth without hitting adjacent objects (e.g. other vessels, piles, marina structure).

Eastern Entrance/Exit

The eastern entrance/exit (hereafter eastern entrance) is approximately 270 m wide (see Fig. 5). On the western side is a rock breakwater and to the east is Wynyard Quarter and various berthing structures on the western edge of Wynyard Quarter. The fairway on the marina side of this entrance varies from approximately 130–270 m wide. The entrance has aids to navigation on both sides (lights: Fl.G.5s5m5M and Oc.R.6s5m5M). In addition, there is a light on the southern end of the breakwater around the marina (Oc.G.6s3m). The entrance has a tidal flow during the flood tide of approximately 0.15 m/s (0.3 knots).6

The eastern entrance is used by most vessels in the marina navigating to, and from, areas to the east (the Hauraki Gulf), including commercial vessels at Z pier, as well as vessels from the Silo Park, Orams and Pier 21 marinas and haul out facilities, the Orams dry stack facility (small boats under 12 m), the dry dock and the refuelling facility. These vessels include superyachts and other larger vessels using the slipway and superyacht berths. In addition, there is a proposal to bring the Kiapara Carrier II, an aggregate carrier of 563 gross tonnes, to a berth within the eastern entrance, with up to four movements per week. Larger vessels, including the Kaipara Carrier II and superyachts, will either have a licensed pilot or licenced pilot-exempt master on board who and will be operating in accordance with the Auckland Council Harbourmaster guidelines.

With strict guidelines around the operation of large vessels, and a licensed pilot or pilot exempt master onboard, the movement of these vessel is extremely well conducted and managed in line with best practice through Auckland Councils Safety Management System.

Vessel masters may also choose to use this entrance to navigate from the marina to the west: the upper harbour and the race start line, as this entrance is easier to negotiate than the western entrance.

6 Proposed Westhaven Pile Berth Redevelopment (Stage 1) Design Report. Beca Ltd 5 August 2015, p.10 and Fig. 2.

Vessels departing the marina through the eastern entrance emerge into an area of the Waitemata Harbour approximately 1.2 km (0.6 nm) from the Harbour Bridge. Other vessels in this area include vessels navigating in the vicinity of the Auckland Harbour Bridge (Harbour Bridge), including bulk carrier ships navigating to and from the Chelsea Wharf, naval vessels navigating to and from the Kauri Point Wharf, scheduled ferries navigating to and from West Harbour, Northcote Point, Birkenhead, Hobsonville and Beach Haven, superyachts, charter vessels and various recreational craft; seaplanes; various other small commercial and recreational craft; vessels approaching the marina, including commercial vessels heading to Z pier, vessels going to the Silo Park, Orams and Pier 21 marinas and haul out facilities, the Orams dry stack facility (small boats under 12 m), the dry dock and the refuelling facility. The greater distance from the Harbour Bridge means vessels departing via this entrance are less likely to come into conflict with vessels navigating in the vicinity of the Harbour Bridge than vessels departing from the western entrance.

Navigation at the entrance

Vessels using the eastern entrance pass thorough a wide area with good visibility (Fig. 5). The width enables a good separation of vessels, even with more than two vessels in the entrance. A straight line approach to the entrance is possible (in both directions) ensuring good visibility and with no risks associated with manoeuvring in a narrow channel.

While the entrance is undoubtly busy at times the width of navigable water, together with the recently granted Westhaven Marina occupation permit which identifies a delineated vessel transiting area (see Fig. 2), help manage potential conflicts between commercial and recreational vessels.

Figure 5. Eastern entrance showing passage route in and out on same scale as figure 3.

Pile Moorings

There is space for approximately 100 vessels to berth in pile moorings in two rows inside the marina to the east of the western entrance. The narrow western entrance creates an increased tidal flow [at flood tide of approximately 0.2 m/s (0.4 knots)].6 This tidal flow can create problems for vessels berthing in the area. Mooring to pile moorings is particularly difficult as pile moorings do not have pontoons so can be more difficult to tie up to compared with berths alongside pontoons.

Mooring to a pile mooring requires placing the vessel in a position to pick up four lines attached to four piles. The vessel is not held in a stable position until all four of these lines are attached. Any cross tidal flow will make approaching the piles, and holding the vessel in position while the lines are attached, more difficult.

Marina Fairways and Traffic Hubs

Maritime rule No. 22.9 applies to vessels in a narrow channel and states that ‘A vessel proceeding along the course of a narrow channel or fairway must keep as near to the outer limit of the channel or fairway which lies on its starboard side as is safe and practicable’. Vessels leaving the marina depart from a berth or mooring, move to the starboard of the channel and then must join the starboard side of the main fairway, which has a width that varies from approximately 20–80 m. Vessels then turn at points A (to exit via the western entrance) or B (to exit via the eastern entrance or access areas to the south e.g. the fuel berth). The areas where any pier or row of moorings joins the main fairway will have converging and diverging traffic, but the two main areas where traffic converges and diverges from multiple directions are at hubs A and B as shown in Fig. 5 These two areas have navigation safety implications arising from the flow of traffic and the need for collision avoidance.

Figure 6. Existing areas of traffic convergence/divergence

Hub A is approximately 2800 m2. At hub A, any vessels using the western entrance and vessels in berths rows A to U using either entrance will converge (see Fig. 7). As can be seen in Fig. 7, there are multiple points where vessels may cross the line of another vessel due to the constrained size of the area and obstructions to clear views caused by the moored vessels. Thus, there is an increased risk of collision at this point.

Figure 7. Traffic convergence/divergence at hub A for western entrance

Hub B is approximately 7800 m2. At hub B, vessels using the eastern entrance will converge (see Fig. 8). There are likely to be more vessels navigating at hub B than hub A. However, it can be seen in Fig. 8 that traffic flow is clearer here, compared with hub A. and there are less points where the paths of vessels may cross. In addition hub B is substantially larger than hub A, allowing for more room and better visibility for navigating vessels. The recently granted occupation permit (see Fig. 2) manages potential conflicts between commercial and recreational vessels), providing a delineated vessel transiting area.

Figure 8. Traffic convergence/divergence at hub B for eastern entrance

PROPOSED SITUATION

The Application includes an extension for the western breakwater to connect to the eastern breakwater to provide public open space and parking. The public open space has been designed in conjunction with local iwi. The proposal also includes the conversion of existing pile moorings to pontoon berthage (see Fig. 1). The new berths will be built according to Australian Standard AS3962-2001. This in compliance with best practice in relation to the layout of the piers, marina berths and the access channels and is used throughout NZ marinas. The access channel between pier A and the new marina berths will be approximately 40 m, in line with other access channels in the marina.

Navigation safety implications may arise from the bridging (closing) of the western entrance, the presence of marina berths where pile moorings are currently located and the construction of the marina.

Construction

The proposed marina breakwater extension will be formed using dredged material from the marina using a dredge mounted on a barge. Dredging will be carried out under an existing maintenance dredging consent held by Westhaven Marina.

Any additional navigation safety issues arising during the construction of the breakwater and the new marina berths should be similar to the existing issues that arise during current dredging. In these cases a dredger and associated traffic are operating within the marina, effectively blocking access ways and restricting access

to some parts of the marina. There are no reported incidents involving navigational safety issues with the current dredging or maintenance operations undertaken at the marina over many years.

These issues should be easily addressed with a Notice to Mariners and, if necessary, suitable signage to make marina users aware of the issue e.g. dredging and construction operations.

Marina Berths

The new facilities will cater for approximately 117 new marina berths replacing space for approximately 125 pile moorings, a slight decrease in vessels using the space. Some pile moorings will still be available in the marina. Marina berths, with a pontoon facility, are more user friendly compared with pile moorings, offering with walk-on, walk-off access and easier berthing. In general, marina berths are more likely to be used than pile moorings and are a more efficient use of space. With a pontoon berth, a vessel master has several options for holding the vessel stable while berthing. The vessel can be brought alongside the berth and a crew member step off onto the pontoon to hold the vessel or once one spring line has been picked up, the vessel can steam ahead on the spring to hold position while the rest of the lines are secured. Alongside the pontoon the vessel can be secured with only two lines. A cross tide or wind may be helpful in some cases if berthing can be timed so that the tide is pushing the vessel onto the pontoon when arriving and off the pontoon when departing.

When entering or departing from a pile mooring a vessel is not held in a secure position until at least both head line and both stern lines are secure. Further to this there is no pontoon or similar structure to assist the master in remaining in the correct position. Pile moorings require a higher level of competence from the vessel master and are more susceptible to issues with cross tide or wind.

Closure of Western Entrance

Vessels affected

Closing the western entrance will mainly affect vessels in the marina navigating to, and from, destinations in the upper harbour and the start line for yacht races. These vessels will have to navigate approximately an extra 0.6 nm to reach a position opposite the start box going through the eastern entrance. This distance would be slightly less for vessels that may ‘cut the corner’ of the eastern entrance. This translates to approximately an extra 7 min travel time (for a vessel traveling at 5 knots). If the start box were to be moved to a position located on the new extension (shown as X in Fig. 9) as has been proposed, this time reduces to an extra 5 min of travel.

Figure 9. Current start box location proposed location

Berthing

Closure of the western entrance will result in a decrease in tidal flow at the entrance from approximately 0.2 to 0.03 m/s (0.4 to 0.06 knots)6. This will result in a decrease in cross tide at the berths (whether pile or marina berths) situated where the pile moorings are currently. The extreme significant wave height will be 0.3 m in the marina down from 0.95 m previously at the eastern entrance7. Thus, closing this entrance will make berthing or mooring in the vicinity easier.

Marina fairways and traffic hubs

Traffic at hub A will now only be navigating in two clear directions (see Fig. 10). Like all pontoon fairways there will be vessels navigating to their berths in each pontoon, but the volume of traffic will be small and will exclude all vessels that previously navigated to or from the western entrance. Closing the western entrance will result in a reduction of risk of collision at point A as traffic will now only be going in two clear directions on either side of the channel as shown in Fig. 10. This will result in less confusion at this fairly narrow point and provide a positive effect on the safety of navigation.

7 Ibid.

Figure 10.Main traffic flow at hub A with western entrance closed.

With the closure of the western entrance the traffic volume at the eastern entrance will increase. There will be an increase in traffic at hub B as all vessels will now transit this area. However, this area is large, already has traffic coming from the direction of the marina and the traffic flow is relatively clear — the only crossing situation is with vessels returning to berths to the south of the entrance to the rows of marina berths e.g. vessels at Z pier or vessels heading to the refuelling facility (see Fig. 8). Any increase in traffic at the entrance or hub B caused by the closure of the western entrance is likely to be small in comparison to the normal traffic volume using the area. Thus, an Increase in traffic at these points is not expected to present any appreciable navigation safety issues.

Existing issues with potential conflicts between commercial and recreational vessels at this entrance have been already identified and the risks mitigated, and clear access further enhanced with the recently granted occupation permit (see Fig. 2), which provides a delineated vessel transiting area. Vessels entering or departing Westhaven Marina are required to use the area to the western side of the entrance as shown in Fig. 2. This provides a clear channel for the use of commercial traffic and other recreational traffic not berthed in Westhaven Marina.

Oil spills

In an oil spill, one entrance will be easier to manage than two. This means that it will be easier to protect the marina from an external spill and easier to contain an internal spill from within the marina.

Start box

Closing the western entrance will allow the start box for yacht races to be moved to a position on the eastern breakwater as the breakwater will then accessible (see Fig.

9). This relocation will result in a reduced distance for yachts in the marina to travel to the start line. Therefore yachts will only have to travel approximately an extra five minutes to reach the start line exiting through the eastern entrance compared with exiting through the western entrance. The start line will be moved further away from the Harbour Bridge. Moving the start line will reduce potential conflict between racing yachts and vessels transiting under the Harbour Bridge, including bulk carrier ships navigating to and from the Chelsea Wharf, naval vessels navigating to and from the Kauri Point Wharf, scheduled ferries navigating to and from West Harbour, Northcote Point, Birkenhead, Hobsonville and Beach Haven, superyachts, charter vessels and various recreational craft. Moving the start line away from the bridge will also reduce the risk of racing yachts colliding with the bridge structure.

CONCLUSION

The proposal to close the western entrance to Westhaven Marina and to redevelop existing pile mooring areas to pontoon berths appears to increase the level of navigational safety in most aspects, and provide safer and more easily accessed and convenient berthing for vessels. The proposal also removes a traffic hub from the inner part of the marina where vessels may not be expecting large numbers of vessels crossing a narrow fairway in an area with restricted sight lines.

Furthermore, the proposal also improves the level of navigation safety to the harbour area north of the western entrance by allowing the repositioning of the yacht race start box, and removing the flow of vessels entering into the harbour area by the Harbour Bridge. Both of these will reduce congestion and vessel numbers in the confined and restricted area of the Harbour Bridge.

There will be an increase in traffic volume at the eastern entrance and the traffic hub at that area. This will have a slightly negative effect on navigational safety, but the size of the area, low percentage increase in the traffic volume, clear sight lines, well-defined fairway areas and the delineated vessel transiting area means we are unlikely to see any negative impact.

Recommendations

I recommend the Start Box is moved towards the east as indicated in figure 9.