When I was growing up I wanted to be Jonny Wilkinson. I loved rugby and played to a decent standard for the county. During Sixth Form at school, I thought about joining the Army and even went to a selection board, but then I went to New Zealand on a gap year and decided on university.

My degree was not exactly relevant to my job. I studied psychology at Exeter. At that time, my brother was a naval doctor working on submarines. I joined him in the Navy because, unlike in the Army, you tend to get a shower in the morning and a bed at night – unless you’re on watch.

After completing my training at Dartmouth, I looked after small arms and machine guns. That was part of my training as a gunnery officer at sea, but I was also an officer of watch. This meant I learnt to drive warships, which is a qualification that transfers into civilian life – it shows I know something about navigation, waterways and driving ships.

During my last year with the Navy, I was naval liaison officer for London and the east of England. I had lots of contact with the Port of London Authority. A job opened up and, for a boy from Essex, it sounded like the dream.

Deputy harbour masters have some wide-ranging responsibilities. We manage major events on the river, as well as big construction projects, while ensuring the safe passage of large vessels. I also enable civil engineers to inspect the road and rail bridges over the Thames – while keeping vital river traffic moving through the bridges. And I examine and test the skills of boat captains and tug/barge skippers who must hold special qualifications to operate a boat on this busy and complex river.

The question I always get asked at dinner parties is whether I open and close Tower Bridge. It’s a common misconception – no, I don’t. The City of London Corporation does that. If you’ve got a tall vessel passing through, they’ll open it for you. You just have to give them 24 hours’ notice.

I work for the Port of London Authority (PLA) which looks after 95 miles of river, from a boundary marker near Teddington Lock to a point out in the North Sea. You can split this into three distinct areas: from the sea to the Thames Barrier, the river’s mainly used for big, commercial shipping; from there to Putney, the focus is on class 5 passenger vessels like the Thames Clippers and City Cruises; beyond that, there’s the recreational bit of the river – the tidal Thames where 75% of all the rowing in the UK happens. We have to make sure all of these things happen safely – within and across those areas.

The tidal range on the Thames is massive. In six hours, the river’s height can rise or fall 7m. This can create serious turbulence around the abutments of all the bridges.

When it comes to traffic control, timing is everything. Huge cruises ships – up to 230m long – are allowed into Greenwich, with some even coming past Tower Bridge to moor next to HMS Belfast. Imagine the size of them next to, say, a rowing boat. To get these vessels to their moorings safely, we have to escort them. We’re also responsible for investigating – and, if necessary, prosecuting – near misses or contacts on the river. If we have to, we can access voice recordings made on VHF radios on board vessels to find out what really happened.

I once helped Tom Cruise perform a stunt on Blackfriars Bridge. It was for Mission: Impossible – Fallout a couple of years ago. They came to us with a request to use drones, speedboats and low-flying helicopters for the scene in which Cruise escapes across the bridge. There were some lengthy discussions but we reached an agreement and sent out a notice to all mariners about the river closure. On the morning – filming tends to happen on weekend mornings when the river’s a bit quieter – we just had to sync the helicopters with the river traffic to minimise the impact. Then Cruise broke his ankle jumping from one building to another and filming was cancelled. We had to come back a couple of months later and do it all over again.

It’s amazing to be involved in big annual events like the Boat Race, but they tend to involve a long planning process. With that one, it takes six months to set up the trial races, make sure all of the launches that follow the race – some of which are very traditional vessels – are river worthy and also make sure crowds are safe. Lots of people turn up early in the morning and, a few hours later, the tide has turned and the foreshore they were waiting on is starting to disappear. Luckily, the RNLI is pretty good at getting them to watch from towpaths these days, so you don’t have too many getting stranded.

At ten minutes to midnight on New Year’s Eve we give the thumbs-up to the event controller for the annual fireworks. That’s the culmination of a huge operation for us. Each year, there’s a debrief in January, then in February the planning starts for the next one. Most of the fireworks are launched from barges on the river, so we have to create a safe zone – there are also 100 passenger vessels and 11,000 people watching from the Thames itself.

My job is very diverse but in a normal week I will mostly be at the PLA office near Tower Bridge. Our HQ is at Gravesend, but I’m more likely to be found at our Richmond office than out there because my team is focused on the river from Teddington Lock to the Thames Barrier. It doesn’t always happen, but I try to get onto the river once a week with our Vessel Traffic Services (VTS) patrol boats.

Even during lockdown we’re pretty busy. The VTS is essentially 24/7 traffic control for the river. Harbour masters like me ensure the VTS has everything it needs to do its job. At the moment, the river is a good way to get essential supplies into London, so we’ve still got lots to do.

We were there for the Westminster Bridge and the London Bridge attacks, shutting the river and helping to establish a safe zone for the emergency services to work in. The PLA is a category 2 responder. This means we support category 1 responders, which are the blue-light services like the Fire Brigade, as well as the London Coastguard. We’re responsible for anything on, under or above the Thames – up to a point called ‘mean high water springs’, which is roughly the high tide point you can see as you walk along the Embankment.

There are some big projects underway on the river. The biggest is probably the Tideway Tunnel, which is all about replacing the city’s Victorian sewage network. Instead of overflow waste going straight into the river, it’s going to be pumped under the river to Beckton, where it will be cleaned and put back into the river. There also big construction sites near Fulham FC’s stadium and at the Battersea extension to the Northern Line.

As part of an initiative called the Thames Vision we’re trying to increase river trade – both recreational and commercial. For example, with those big construction projects, if you can remove waste – the ‘muckaway’, it’s called – by river, rather than relying on lorries, it’s much more environmentally friendly.

My favourite part of the Thames is the Upper Pool. This runs from Wapping Ness to London Bridge. It’s got historic Butler’s Wharf, some of the best and oldest riverside pubs and, of course, Tower Bridge. It’s a really special stretch of the river.

I hope to be harbour master one day. Deputy harbour master is a wonderful job and it’s a pleasure to be involved with the river and all of those major events. I can see myself doing this for a long time.