Craig was born in Scotland and he has a deep connection to the ocean, and these two aspects are part of his identity, reflected in this full sleeve and pec tattoo by joining Polynesian and Scottish elements.
There are waves throughout the whole tattoo, with fish and water elements (manta, turtle, hammerhead shark, shark, fish, fish hook, waves) while an earlier Scottish knot is matched by the tartan of the Buchanan clan, by a Celtic knot, and by a stylized thistle on the pec.

The turtle representing family is central on the shoulder with the front flippers spanning from past to future (flax leaves with a star above the turtle symbolize the importance of this union too).
The couple on the shell protects the two children below, within braids for bond and union, while the Marquesan cross symbolizes harmony.
The sun and coconut leaves enclosing the turtle represent joy and prosperity and there are rows of birds around it to symbolize voyage.

Adversities in the past, on the shoulder blade (the moray eel and path of Kamehameha), brought family even closer (the 4 people with the braid joining them).

The manta on the pec symbolizes freedom, and it includes the warrior and a tiki (the protector of the family).
Ancestors above guard on family too.

On the arm there are three animals to represent his wife and children, over the ahuahu o Mataora.
His wife is represented by the hammerhead shark (tenacity, determination, support), with flax leaves in it for union.
His daughter is the shark, for speed and voyage, and to recall her mother, with the youngest son between them two symbolized by the lizard.

The Celtic knot below is a reference to Craig's origins, and similarly the kumu symbol (origin, tradition) was placed next to the existing Scottish knot, with spearheads and octopus tentacles for strength and tenacity.

The two tiki protect from all sides his family and what they learnt and achieved (the stepping stones).

The following image shows with different colors the individual elements of the tattoo:

Kudos to Shane Gallagher Coley for inspiring the idea of including the clan's tartan within the Polynesian design.