"They're just bloody good passionate Kiwis saving lives on the water. They're just good people," he said.
"There's 2500 New Zealanders who donate their time to be in the Coastguard. They volunteer all their time, they're amazing really. Last year they made over 7000 rescues."
All money raised this month will go towards the Coastguard's volunteer programme, which has about 2500 people involved.
"These volunteers - who make up Coastguard's rescue crews - are local people with regular jobs and families who give up their evenings and weekends to train," Sir Graham said.
It is estimated that volunteers will work more than 307,000 hours and rescue more than 7000 people.
The rugby coach said he was happy to tag his reputation to the work of the Coastguard.
"I'm lucky enough to have a wee bit of profile, thanks to Richie [McCaw], etcetera. Hopefully a little bit of profile will help build some support. I'm only too pleased to help," he said.
Coastguard New Zealand head Patrick Holmes urged Kiwis to get on board, as the money would no doubt help save lives.
"The MayDay appeal will help us ensure we can continue to provide our volunteers with the skills they need to tackle life-threatening situations on the water," Mr Holmes said.
This is the fourth year that a Coastguard MayDay Call appeal has been made.
The fundraising concept is asking New Zealanders to donate an hour's pay to Coastguard: "Whatever your job, please donate just one hour's pay to help us do ours."
• For more info or to donate, visit: www.hourforcoastguard.co.nz
