Grow Northland Rail campaign director Alby Barr said with the prospect of Ports of Auckland being sold or having no space to grow the regional council should be championing its shift to the nearest and only deepwater port at Marsden Point.
Mr Barr also used Murupara as an example where one log train per day took 140 truck units off the highway.
Freight tonnage, logging trucks, road safety and regional development were reasons why the regional council should back the rail link, he said.
Mr Leitch cited a 2012 International Monetary Fund report recommending some public benefit infrastructure be paid for by Reserve Bank credits, such as that which funded the early State Advances housing in New Zealand.
Most of the spoken submissions were on the proposed Pest and Marine Pathway Management Plan.
Presenting a joint submission from Ruakaka Parish Ratepayers and Residents Association and Marsden Yacht and Boat Club, Warren Daniel said both groups thought pest management should be paid for by all ratepayers, not a targeted extra marine rate on local boat or berth owners.
Mr Daniel said the ratepayers and residents group believed biodiversity plans should be nationally co-ordinated.
He also said tougher requirements for anti-foul certification was "the thin edge of the wedge" and would lead to the compulsory registration of boats and owners, which the boating community opposed.
Federated Farmers NZ called for a "multiple organisational, community engagement and collaborative approach" in biodiversity planning, including "terrestrial pathways" for weed incursions.
All local authority plans should be aligned to and consistent with national ones, Federated Farmers said.
Similar was said by the Ministry for Primary Industries (MPI). Also, the regional council's plan needed a stronger cost benefit analysis to shore it up against people taking the council to the Environment Court.
For Bream Bay Coastal Care Trust, David Lourie called for the regional council to disallow kiteboarding in the Ruakaka and Waipu estuarine wildlife reserves.
The boards, classified as small sail boats, should not be exempt from the 5 knot speed limit within 200m from shore.
The estuaries were too narrow for any board to be 200m from the shore, and there was evidence that kiteboarding disturbed the habitat of protected shorebirds, Mr Lourie said.
The hearings continue Wednesday at the Bay of Islands Yacht Club, Waitangi.