Bay of Plenty iwi say land confiscations in the 1860s could scuttle any chance of gaining customary title to tracts of the foreshore in their area.
From Orokawa Bay near Waihi in the western Bay of Plenty to Hawai on the eastern shores, Maori own 157.1km, or 21.3 per cent, of land abutting the foreshore.
A number of tribes have foreshore interests, including Te Arawa hapu, Tuwharetoa, Ngati Rangitihi, Ngati Awa, Te Whakatohea and Ngai Tai.
However, in and around Tauranga harbour, three iwi - Ngati Ranginui, Ngati Pukenga and Ngai Te Rangi - say Crown raupatu, or confiscation, of 117,358ha of their lands during the 1860s after the battles of Gate Pa and Te Ranga will make gaining customary title - a limited form of ownership because the title can't be sold - problematic.
That is because customary title tests require Maori to have exercised exclusive use and occupation of the area since 1840 with no substantial interruption to qualify.
Awanuiarangi Black, from Ngati Pukenga, says that confiscation was a "pretty significant" interruption.
"It pretty much counts all of us in Tauranga out because of the raupatu from 1865.
"Everything from Nga Kuri a Wharei near Waihi Beach down to Papamoa - the whole lot was taken."
Complicating matters is that some land was returned to Tauranga Moana tribes.
"That which was returned, well, that process wan't complete until the 1880s. There's a long period in between in law that says that we didn't have occupational ownership."
Antoine Coffin, from Ngati Ranginui, said the tests effectively marginalised Maori rights by narrowly defining customary title.
Ngai Te Rangi's Hauata Palmer lives on Matakana Island, just off Tauranga's coast.
The island was part of confiscated lands which was partly returned to individualised Maori ownership but also had blocks sold to non-Maori.
Mr Palmer said it was a "double standard" that if iwi did gain customary title public access was guaranteed, but private land owners who already had title to the foreshore were not subject to the same conditions.
The whole repeal process had left a sour taste. "You know, I think it's abhorrent that the thief determines what the conditions are for the return of the land."
Asked if raupatu would hamper Tauranga tribes' chances, Attorney-General Christopher Finlayson said it would be inappropriate to discuss individual applicants before the bill had passed.
Changes to foreshore rights
2004 Foreshore & Seabed Act:
* Stopped Maori from accessing courts to prove foreshore claims.
* Foreshore defined as wet sand out to 12 nautical mile limit.
* Crown owns foreshore and seabed.
Marine and Coastal Area Bill:
* Replaces 2004 Foreshore and Seabed Act.
* Creates "common marine and coastal area" where no group owns the wet sand, unless Maori apply for customary title.
Tests to qualify for customary title:
* Maori must prove exclusive use and occupation since 1840, with no substantial interruption.
* Area is held in accordance with tikanga.
* Customary title cannot be sold.
* Public access is guaranteed.