Chainsaws?! Suggesting the vegetation is very dense. What on earth are they hoping to find buried under it?!
A couple of years ago I did some photos around that area;
That last photo, as a schoolboy in the 80s I have changed in those huts for a competitive game of footy for real!
I don't want to spam your thread with useless info, but I'm happy to provide background and detail on this area of Hull if Google maps isn't quite enough.
This park is still big with kids and local dog walkers, it hasn't quite taken the seedy side like other parks around Hull have.
Easy access to the river, as this collection of rundown buildings is around the old boathouse, which has wooden long steps going down the muddy bank. Areas of Beresford Park has that abandoned feel, but it has a very high footfall from the locals; it has a skate park which is very popular; the pond they have been searching is a fishing pond, which is surrounded by a ring of trees bushes and scrub acting as wildlife patches, and has dozens of little jetties around it. They have well attended fairs around this pond, and this pond is always busy and popular during the summer.
The river has a medium class housing estate of mainly working families that backs onto it and the park, lots of people come to this park especially to walk dogs, it has football and cricket pitches. And there are no fences or barriers to the river. While there's nothing formal along the river, it's a popular spot in the summer evenings and is a great spot to catch sunsets. There are always lots of teens around the park, particularly this boathouse area, where they like to sit on the river bank at the top of the steps watching the sun go down.
It hasn't sunk to the seedy depths of other parks, so there's still lots of conversation among strangers around here. I'd often stop and chat to dog walkers, groups of teens, anyone passing, people are always happy to say hello, it's always been a park with a good vibe. It's not a river for tourists, but sometimes a cruiser will come down this river from Beverley Beck aiming for the Humber and inland via the Ouse or the Trent. Rare though.
If you follow the river bank to the south, past the big wind turbine, there is a footpath that can get a little hairy that makes it to the road bridge at Ferry Lane. It just squeezes in between the back wall of the industry backing onto the river, mainly car wreckers, and the river.
The main point about this park is that it is easy access, it has multiple points of access and has very little boundary fencing. When it is locked at night it is only a road gate to keep cars out, there is no real way to shut this park, it is open on all sides and just merges into its surroundings. Only around the wind turbine is there secure fencing. And there are lots of small entrances too.