We found this on this website and it seemed pretty appropriate for us considering our circumstances:
Often a swallow is the "first sign that land is near". To a sailor the swallow means a "safe return home". Swallows are known to travel far distances out to sea during migration and would rest on boats close to shore which gave early mariners the first sign that land was close by. Swallows also return home every year, no matter where they are, a source of comfort for sailors far from home.
Swallow tattoos are also associated with loyalty and fidelity - swallows choose a mate for life, and will only nest with that bird and no other.