A drop in beach levels between two seaside towns could result in land and properties being lost to the sea, according to Conwy council.
Beach levels have dropped three metres in some places
The authority wants public comments on four options to save the sea defences between Rhos-on-Sea and Old Colwyn.
One businessman said he wanted the council to use the opportunity to create a marina as a combination of sea-defence and job creation.
An exhibition was held on Sunday, but emailed comments are still invited.
According to the council the sea wall is in poor condition and at risk of being undermined by falling beach levels.
"In some places beach levels have dropped by up to three metres in the last 50 years," said a spokesperson.
Levels were much higher in this picture taken in 1937
"This causes problems such as occurred at Old Colwyn recently, where emergency repairs cost in the region of £100,000 and closed the promenade for three weeks.
"If allowed to deteriorate further, the promenade road, coastal properties and eventually the railway are at risk of being lost to the sea."
The council is looking at four options.
The cheapest is to place rocks at the toe of the existing wall, while the most expensive is to reconstruct the sea wall.
Neil Formstone, who runs three businesses near the seaside, said water sports were vital to the Colwyn Bay area.
"I want the council to use this opportunity for expansion in the town, to turn it around and create a marina," said Mr Formstone.
"People should not jump in and think 'let's stop the sea' - we should be asking what advantages can we get from it, even if it means to have to wait 12 months to get the right plan."