The contracts, worth $94.8m, will last for up to two years.
The rigs are owned by Scott and English Energy, which has just been taken over by Swissco.
Its latest contract comes a few days after the company recorded a $2m profit for the second quarter of 2014.
Sales increased from $10.4m to $11.2m due to higher revenue from the chartering and ship repair business segments.
Swissco operates a young fleet of 31 vessels, including anchor handling tugs (AHTs), utility tugs, barges and accommodation vessels.
