Spithill's family had never previously met the McKee family.
New Zealand-based Aaron Torenson, who has been friends with Jimmy Spithill for about 15 years, confirmed Pellew and Spithill supported McKee - who was then a stranger to them - the day after the accident until family members arrived that evening.
"They just literally immediately got into gear and went up [to the hospital] and started communicating with the family back in New Zealand, bought him a cellphone, loaded all the family numbers into the phone for him, stayed with him, talked to the doctors, shared information with the family overseas."
He said Pellew and Arthur Spithill exchanged contact details with McKee and planned to keep in touch with him after leaving Bermuda.
Arthur Spithill declined to comment publicly about helping McKee and the Herald was unable to reach Pellew on Friday.
Jimmy Spithill is debatably the Aussie sportsman Kiwis love to hate most - known for his quick wit he's been known to take digs at his rivals.
After a win over Team New Zealand last weekend he told journalists: "Both times we've raced Team New Zealand they have made some pretty fundamental mistakes ... at the start line today and obviously at the top mark again."
However, Torenson said his mate has a kinder side and is passionate about New Zealand.
"Jimmy's an absolutely ruthless competitor and he's in war mode right now. But he and his entire family are the absolute salt of the earth - do anything for anyone kind of people - so there's no surprises that they [helped McKee]. They're an amazing family."
Jimmy Spithill met his American wife Jennifer while competing here in the 2003 America's Cup, later marrying in Queenstown.
The couple owns property in Auckland and Torenson said Spithill came to New Zealand on a hunting trip every year.
In Bermuda, the investigation into Mary McKee's death is ongoing.
Police arrested a 26-year-old local man who they say was the driver of the boat that crashed into the vessel the tourists were in, believing he was impaired while operating the boat.
The man passed a breath test and was released on bail, with strict conditions.
Police said on June 4 that they expected McKee to be released from hospital that day.
It is unclear whether he is still in Bermuda or has returned to New Zealand.
Attempts by the Herald to reach the hospital were unsuccessful today.
The Ministry of Foreign Affairs and Trade (Mfat) said the Ministry was supporting Mary McKee's family.
A spokesman told the Herald he was unable to release further details about how Mfat was assisting the family due to privacy reasons.