Everyone ignores him. Eric rubs his forehead, stands back and watches.
"Come on, Eric!" shouts Barry, he of the bullhorn throat. "Put some energy into it! This is supposed to be a team effort!"
"But..." starts Eric, "I honestly think that it would be a good idea if you thought about this a bit. You need some sort of framework to tie the drums to, or when the rope gets wet it'll expand and..."
"Oh, look!" Sheila stands up from tying reef knots, and puts her hands on her hips. "We can't do this without everyone's co-operation."
Eric rubs his forehead again and, heaving a quiet sigh, walks over and joins in.
Sometimes I witness things that make me eternally grateful that I don't have a real job after all. At least, at the end of the day, I can leave where I'm working and forget all about it; at least I don't have to lie awake at night fretting about real and imagined slights, and wondering how they affect my position in the political world, and at least - thank you, God - no-one forces me to take part in team-building exercises.
But I do get to witness them. I am playing Miss Facilitator - which means that I know where the sticking plasters are, and have a clock and a list of who is supposed to be in which team, tucked under my arm.
The sales force of this air-conditioning company spends its afternoon down by the upper reaches of the Thames attempting, in teams of eight, to build a raft from a pile of oildrums, planks and rope, - and get to the other side of the river for the next part of their company Awayday, which involves a lot of drinking.
I'm still not entirely sure how building a raft relates to persuading people to ventilate their offices, but the human resources officer of Eazibreez obviously believes that it does, so here we all are.
I think I know what's going on: Eazibreez are in difficulties, and redundancies are in the air. As the 24-strong sales team sweat and struggle and their personalities come to the fore, HR strolls up and down the bank and watches them, scribbling notes on her hand-held computer.
And because everyone is aware that this is what she's doing, they are exaggerating the qualities that they think she's looking for in the surviving employees. Barry thinks it's leadership she wants, so elbowed his way forward before we had even got off the coach to start organising "his" troops.
Sheila obviously believes that it's being a team player that counts. Eric, on the other hand, hopes that HR will see that he is a man of reason, someone who can actually come up with solutions.
Whatever she's really after, the result is chaos. The team have lined up nine oildrums in sets of three, and are lashing them together. I'm no Girl Guide, but even I can see that it's not going to work.
Nice Eric picks up a plank and comments: "If we at least put a couple of these diagonally..." but Barry replies: "We haven't got time for that. It doesn't have to look good, it just has to get us across before the others."
"But..." says Eric.
"No!" snaps Barry. "No arguments!"
HR stops, scribbles something, moves on.
With Barry standing to one side to oversee the heaving, the team bend and, vertebrae popping, drag their raft, sagging in the middle, into the river, where it bobs innocently in the sunshine.
Sheila suggests team-centred leg-ups, and four people finally scramble onto their makeshift craft. Eric stands quietly on the bank, specs glinting, and watches as they take a corner each and begin to paddle.
A groan from a straining rope, then another, and the centre drum erupts into the air, catches the heaviest paddler on the back and pitches him into the water.
One-by-one, the remaining barrels pop from their moorings and shoot away from beneath their passengers. They splash back to land and stand, dripping and puffing, as the barrels bob in the sunshine.
"Well," says Barry, displaying that other fine leadership quality of sidestepping the blame. "That was a pretty disastrous effort. Does anybody else have any clever suggestions?"