He previously arranged flying days at Rand Airport to share his passion for aviation with people from disadvantaged backgrounds.
Forum member “Eitai2000" wrote: “RIP Essie, you were a man with a great heart, and helped me and so many others in our passion for aviation.”
Another aviator, JP Schulze, wrote that Esterhuysen changed the course of his life forever.
“You taught me about candour and paying it forward,” he said. “You were the most principled, ethical man I've ever met, and I stand amongst hundreds echoing the same words. The world is poorer without you. I'm gutted.”
Forum members also speculated on what had led to the crash. A flight that Esterhuysen had done many times previously, forum members speculated on whether he had misjudged his height over the water as he came for the landing.
Judging altitude over calm bodies of water is notoriously difficult and can lead to pilots thinking they have more height than they do.
It was also officially after sunset which would have made judging the terrain much harder, they said.
Other possibilities could be a medical emergency or that one of the dogs managed to wriggle out of its harness and cause a disturbance at a critical moment of flight.
The SA Civil Aviation Authority (CAA) would conduct an investigation into the crash, spokesperson Kabelo Ledwaba said on Friday.
On Saturday, Jake Manten, the National Sea Rescue Institute’s (NSRI) Vaal Dam station commander, outlined the roles that its members had played.
The NSRI duty crew were alerted to reports of a helicopter accident at the dam after 6pm on Friday.
“On arrival on the scene, near to the Vaal Marina, 200m offshore, a Robertson-44 helicopter was found to have ditched in the Vaal Dam,” he said.
A bystander rowed out the crash site in a small boat and recovered Dané's body.
SAPS divers recovered Esterhuysen's body the following day. The wrecked helicopter was also dragged ashore.
Elsa van Zyl, a family member, told Netwerk24 Esterhuysen was bringing Dané to his Vaal Marina home to spoil her with a weekend away. She managed his guest house in Wilderness along the Garden Route.
She said Esterhuysen loved to entertain people on the dam.
Esterhuysen leaves behind his wife, Mariana, and son Marinus. Dané leaves behind her daughter, Géla le Roux, former Miss SA 2018.