The Falkirk-based company has bought Tech Safe Systems, which it describes as the UK's top supplier of launch and recovery systems for remotely operated underwater vehicles, for an indisclosed sum.
The acquisition will give Outreach a presence in the market for the supply of specialist support services for ROVs.
The deal comes at a a time when demand for ROVs is increasing amid a surge in investment in the North Sea where oil and gas firms are trying to boost output to meet strong demand.
Spending on new UK North Sea assets reached a record £14.4bn in 2013 with a further £13bn investment expected in 2014.
Many Scottish oil services firms have benefited.
The acquisition is expected to help Outreach maintain the rapid growth it has recorded in recent years.
Outreach has trebled turnover to £15 million since 2007, when directors Gary Potts and Derek Payne acquired the company in a management buyout that reportedly valued the firm at £3m.
Employee numbers at the firm have more than doubled, from 40 to 95.
The company specialises in supplying handling, lifting and access equipment used in industries like oil and gas and construction.
Mr Potts said: "Tech Safe Systems has carved an attractive niche in the ROV market which is entirely complementary to what Outreach currently offers in the offshore oil and gas, renewables and marine sectors. We believe there is strong potential to grow the business."
Based in Great Yarmouth, Tech Safe Systems employs 22 people including skilled specialist engineers.
Outreach said it plans to recruitment more employees over the next 12 to 18 months, mainly on the service side, to support growth.
Santander provided an undisclosed amount of debt in support of the acquisition.
In April a study by Ernst & Young found companies in the UK's oil and gas services industry generate £35bn total revenues a year globally with the value on track to increase, fuelled by investment in the North Sea.
Around half the oil and gas services businesses the accountancy firm counted in the UK were Scotland-based. It studied the accounts for 2012 filed by 1,585 UK firms at Companies House
Tech Safe was started in 1996 by Peter Evans, who spent a number of years piloting manned submersibles and working in the offshore industry.