Yellow buoys have appeared around Mokoia Island in an attempt to slow erosion.
The buoys inform boaties of the 5-knot speed restriction that is in place not just around the mainland but islands as well.
Mokoia Island Trust chairman Rawiri Bhana said the wake coming from boats was causing the island to erode and he was scared the island could one day disappear.
"The erosion that we are getting from boaties that are out there fanging it, whether they are on jet skis or boats, the wake actually is eroding the island itself."
Bhana said places like Hinemoa's pool which was on the lake edge, were affected.
"A constant swell creates the possibility that the lake wall which holds the water back, will go."
Bhana said he had seen detrimental effects of the island shrinking through aerial photographs and seen land which was present 50 years ago disappear.
He also raised concerns that the 40 kiwi on the island and other native species that used the island would have no home if erosion continued.
"We are currently a breeding ground for kiwi and black robin so we have a partnership with the Department of Conservation where we trans-locate these species to other places in the country that don't have them.
"What happens in the lake doesn't just affect those on the mainland it affects the island which is home to a load of native species."
Mokoia Island is the setting of the legendary love story of Hinemoa and Tutanekai which is well known throughout New Zealand.
Bhana said the island had historical significance to all iwi in Rotorua and knew the island was an iconic sight for those flying or driving over the hill into Rotorua.
"Part of us protecting and preserving those stories is that we don't want to one day bring people to the island and say where this bit of lake is is actually where Hinemoa's pool used to be but it is now underwater.
"We have this beautiful jewel and we want it to still be a jewel instead of slowly disappearing in front of our eyes."
The buoys have been strategically placed 200m away from the jetty and grassy areas of the island which is where Bhana believed most boaties would see them.
Bay of Plenty Regional Council harbourmaster Peter Buell said speeding within 200m of the shore and within 50m of other floating structures and people in the water, was a rule often overlooked by boaties.
"The 5-knot buoys aid in educating lake users on where they can and cannot speed safely.
"Most people struggle to gauge 200m."
Buell said the lake around Mokoia Island was a high traffic area and therefore had a higher risk for collisions.
"With commercial operators going to and from the island, dropping off and picking up passengers, it is important that skiers and fishing boats aren't flying past putting everyone in danger.
"There is a shallow area to the north of the Mokoia Island jetty, which often catches boaties out."
Buell said the installation of the buoys did not change any of the rules which previously existed, it just made following them clear.
"Stick to the 5-knot rule and don't let your next trip be your last."