Earlier this month organisers rejected the idea of finding a new venue, saying they had instead agreed with the Polynesian government to build a "more moderate" judges' tower.
But Slater, an 11-time world champion, was unimpressed by the revised proposal, and the issue has sparked fierce local resistance.
"Doesn't make any sense to need such a giant tower for a 2 days event," Slater commented in response to a video posted by local surfer Matahi Drollet, who condemned the compromise reached by officials.
"Give the money to local infrastructure in the town for all the damage done from changing the river that caused floods earlier this year," wrote the 51-year-old Slater.
Several hundred people have been protesting at the site near the beach of Teahupoo –- one of the world's most famous surfing areas and the designated Olympic venue -- against plans to erect a 14-metre (46-foot) aluminium structure in the water for judges to better assess the competition.
Local associations argued the installation would damage corals beyond repair. An online petition against the project has attracted more than 168,000 signatures.
The revised installation will match a previous wooden tower in size and weight, reducing the weight on the foundations. This, in turn, would reduce the depth of drilling, organisers said.
Slater suggested using the existing wooden structure, or to "rebuild the frame on (the) same footing".
However, the organising committee told AFP the wooden tower "has not been up to standard for about 10 years".
Moetai Brotherson, President of French Polynesia -- which comprises more than 100 islands including Tahiti -- initially suggested a different spot for the competition, without the need for a tower.
But an agreement was eventually struck to modify the tower plans and keep the surfing events in Teahupoo.
"The solution we are proposing, in the unanimous opinion of the committee of experts, is the best one possible," Brotherson told AFP in Paris last week.
