The boat, named “Adventure”, is owned by Aberdeenshire brothers Ollie Ferguson, eight, and Harry, five and was launched off the coast of Mauritania in November.
The brothers from Peterhead, Aberdeenshire, had hoped the boat would reach America.
But it is starting to run low on battery and it’s feared the little boat’s tracker will fail, meaning the boys will never know if it has reached its planned destination.
The kind-hearted crew from the 228m long Stena Carron have now offered to help find the boat if it comes close to their position.
The crew says they will recharge its batteries and send it back on it’s way to American soil if they find it.
The vessel was launched as part of a “sandbucket list” of 500 adventures set up by the boy’s father MacNeill Ferguson.
The family’s adventures are being chronicled on their Facebook page “The Days are Just Packed”.
So far the boat has braved the rough seas and strong currents across 2,000 miles of the southern Atlantic.
The pirate ship, which can be tracked online, is now around 100 miles off the coast of Guyana and around 35 miles from Stena Carron, a ship owned by Aberdeen-based Stena Drilling.
The family remains positive about the venture, despite a recent change of course which means the Stena Carron may be unable to save it.
Dad McNeill said: “We have been watching her make her way across, facing waves about 20 metres high.
“It’s amazing that she has made it all the way across to Guyana.
“There were problems with last week when she didn’t ping and we were contacted by people on Stena Carron and I ended up speaking to the offshore installation manager who said if its comes near to them they would pick her up for us.
“They had all 160 crew looking out for it. They were all on this rescue mission for our little boys’ boat.
“I think she came about 35 miles away from the Stena Carron.
“It was too much to ask them to go all that way from the rig, but they told us to keeping sending co-ordinates and they are going to keep on looking out for it.”
Adventure is currently on course to land somewhere in the Caribbean - but without the tracker, its landfall may remain a mystery.
If it is returned home, the ambitious boys plan to set it off again, this time across the Pacific.
Stuart Greer, operations manager with Stena Drilling, said: “We have alerted the other vessels in the area and may still be able to intercept it with one of the supply vessels. We’ll keep in touch with the family and continue to monitor.
“If it turns up in Guyana or Trinidad we have offered to have it transported back to the UK as the family have indicated they would like to begin the adventure but this time in the Pacific.”
Adventure’s progress can be tracked via its dedicated website at: track-adventure.squarespace.com