Investigations into Mother's Day drowning continue

A toddler drowned after the boat he & his family were travelling in capsized on Hartbeespoort Dam.

Police divers on the shore of Hartbeespoort Dam conducting a search for missing toddler who fell out of a capsized boat on 11 May 2015. Picture: Louise McAuliffe/EWN.

JOHANNESBURG - The South African Maritime Safety Authority (Samsa) said on Thursday it's making progress in its investigation into a boating tragedy on Hartbeespoort Dam, in which a toddler drowned.

It's believed speeding led to the accident on Sunday.

Twenty-three-month-old Zandre Vosloo was found nearly 24 hours after the boat capsized, throwing his mother, two siblings and the vessel's skipper into the water.

WATCH: Toddler's body recovered from Hartbeespoort Dam

Samsa's Sobantu Tilayi said they have been investigating the skipper's qualifications.

"The skipper was fully certified and the boat was surveyed in April.

He said they are also looking into claims made by witnesses.

A man who assisted in the recovery of the family after their boat capsized has claimed that the parents were under the influence of alcohol.

Tilayi said, "We cannot speculate on the soberness, because we don't have facts to lead to that."

Witness Gerrit Tromp and his family were on the dam when the rubber duck capsized.

He claimed he could smell alcohol on the mother, the father and his friend who were slurring while he was trying to get them out of the water.

Tromp said they were also swearing at him as he searched for their toddler.

Tilayi said the skipper could be charged for not ensuring that the three children under twelve had life jackets.

Tromp also said the skipper was driving the boat recklessly before it capsized.

He said the skipper had attempted to throw two occupants off the tube behind the boat into the water.

"The boat capsized due to the manoeuvres he was making, no other means; there was no big wake, no other boats"

The Vosloo family has not yet been reached for comment.

A separate police investigation is also expected to establish the boy's cause of death.