The regulatory authority is determined by an MOU, in this case, between WorkSafe NZ and Maritime NZ - essentially, when you step off the gangplank it becomes Maritime NZ's domain.

I'll give some thought to the bigger question of 'whose responsible': first principles - the entity that creates the risk must take responsibility for the risk. therefore the Marina (Company) must ensure the marina, dry dock and boat hoist are fit for the intended purpose, and the person undertaken the repair and maintenance work must ensure its done is a manner that mitigates the associated risk. There'll be a whole lot of grey and fine print in there though.

Understand one thing, unlike the other H&S regulator, Maritime NZ will investigate any and all incidents that fall within it's remit, and won't hesitate to bring a prosecution, regardless of where the "incident occurs" or who it involves, private or commercial

Check out their website to see how seriously they take things https://www.maritimenz.govt.nz/public/news/

A lot of the investigations they carry out will be similar to Civil Aviation's investigations - s safety investigation, rather than a prosecution one. CAANZ and MNZ have a dual-remit, under their respective Acts, as well as the HSaW Act MoU with Worksafe. Essentially any H&S investigation is carried out on Worksafe's behalf.
At least that's how CAANZ have explained it to me, and I don't expect that it would be different to MNZ.

As to who to report an incident to, in the example above it gets reported to MNZ, and as part of their MoU with Worksafe, they forward to report on. The reports I've filed with CAANZ, I've always verified that it is passed on.

The key point to keep in mind here is that the HSAW Act, and WorkSafe's jurisdiction / remit only applies to workplaces and people undertaking work. A private boat owner working on his own craft on land in the marina precinct, or elsewhere, is not within WorkSafe's jurisdiction, nor MNZ's. Historically before MNZ, CAANZ, NZ Police, NZTA became "agencies" of WorkSafe under MoU's (because of their specialist subject matter knowledge and expertise) the boundaries were more clearly defined. E.g. OSH /WorkSafe had jurisdiction on wharves up to the waters edge, and MNZ's jurisdiction was "afloat". MNZ had jurisdiction over shipboard cranes, WorkSafe over the slings and loading gear. Commercial activities on the marina (land-based) was WorkSafe's jurisdiction. The floating jetties and "on water" activities was MNZ's jurisdiction. The HSAW Act now extends the definition of a workplace to include commercial activities on a water body. MNZ and CAANZ also have International standards and laws to monitor and apply within their jurisdiction. This can influence their approach to investigations in these environments.

Every agency conducting a H&S investigation should approach the process in the same way. Unfortunately that hasn't / doesn't happen and so a wider variation in outcomes results. There is no consistency of approach.

The objective of every H&S investigation should be to identify those contributing factors that influenced or enabled the damage / loss / harm event to occur, either through their presence or the absence. The subsequent analysis of those factors should determine which were potentially controllable, whether the outcome would be different if the controls were in place, whether the damage event was reasonably foreseeable or not, whether the controls were available and able to be implemented, and if so would a lower level of damage have resulted. There are a number of other considerations in the investigation process that must be examined before decisions about accountability and prosecution are considered. Commencing investigation with a view to prosecution is a flawed approach in the health and safety context because it is based on assigning "blame" and holding the blameworthy to account. It it "encourages" bias, narrows the scope and thinking, does not treat all causative factors equally, and is an egocentric model. This is essentially the Police model of investigation, i.e. ascertaining whether or not a crime has been committed, gathering evidence to support the contention that a crime has occurred, and examining the evidence in order to join the dots to a suspected perpetrator.

Unfortunately this the Model that OSH / WorkSafe have been following since the mid-1990's, and I don't expect the other agencies vary much from the same Model. The results will continue to be underwhelming!

I note that Nippin Anand is visiting these shores this year. What opportunities might his visit create in this regard?

Not the way MNZ cases are reported Aaron, the way I read them MNZ investigates, and then brings a persecution, as in this case:

Young admitted a Maritime NZ charge that on November 27, 2021 he operated the 8.5m craft C-Works, on a fishing trip with friends and work colleagues, in a way that caused unnecessary danger or risk.

Unfortunately this the Model that OSH / WorkSafe have been following since the mid-1990's, and I don't expect the other agencies vary much from the same Model. The results will continue to be underwhelming! — Rowly Brown

Maritime NZ investigates, and if prosecution is warranted, they charge and usually successfully so. They brought a successful prosecution against one of my former clients under the 2015 HSW Act for a shipboard accident when the vessel was in the South China Sea

Asked the question of MNZ Aaron,who prosecutes cases that MNZ investigate,and their reply was they do on cases that infringe Acts and Regs they oversee, and in consultation with other Regulators, this page explains the wheres & hows

https://www.maritimenz.govt.nz/content/about/what-we-do/compliance/MNZ-prosecution-policy.asp#intro

Just over a year ago, I put up a post about the fire alarm going off in my town, summoning the Lyttelton Volunteer Fire Brigade to a workplace accident down on the Coal Wharf at Port Lyttelton.
Today Maritime NZ laid charges against the Lyttelton Port Company, while this will provide cold comfort to the family of the worker killed, at least they will have their day in court seeing someone held to account https://www.maritimenz.govt.nz/public/news/2023/april/charges-laid-following-two-fatal-incidents-on-ports-in-april-2022/
Charges have also been filed by Maritime NZ in relation to a fatal accident that occurred at The Ports Of Auckland six days earlier- it may have taken just over a year to get these cases to trial, but Bravo Zulu Maritime NZ :up:

An Auckland diver is in critical condition after an incident at an East Auckland wharf.
He was rushed to hospital from Half Moon Bay Marina on Wednesday afternoon, after diving from a Sealink vessel in their Marina terminal, Maritime NZ confirmed.

Multiple Regulators Involved After Diver Critically Injured