Waiting in the marquee in Clyde Square as Her Majesty and Prince Philip walked inside were the Inverclyde Tourist Group, Ocean Youth Trust, Port Glasgow Otters and Inverclyde community Development Trust.
The Queen headed straight for the Inverclyde Tourist Group and it was not the first time some of the volunteers had come face to face with the monarch.
The charity dedicates its time to greeting and offering tours to cruise ship visitors - in turn helping to boost local tourism.
Volunteer Eleanor Robertson MBE, who received her royal commendation three years ago for her work in the community, said: "The Queen was very friendly and spent a few minutes talking to us.
"She was particularly interested in the fact that we are all volunteers."
Bob Webster, also from the group, added: "I think it is important to say that we were very lucky to meet the Queen but we are just a few of many who do a fantastic job."
The Duke of Edinburgh stopped to talk to members of the Port Glasgow Otters.
Swimmer Angela Edmiston, 23, from Greenock, said: "Prince Philip asked us about the club - he was very nice and friendly.
"He asked me what strokes I do and I told him I do the back stroke, breast stroke and front crawl."
Angela, who has been a member of the otters for 17 years, said: "I was a bit nervous about meeting the royal visitors but they were really nice and seemed genuinely interested in the Otters."
Mum Jessie Edmiston added: "It has been a fantastic day."
Prince Philip also spoke to local organisers and young people of the Ocean Youth Trust which works to inspire young people to make positive changes through sailing.
Member Dean Zielenski said: "We do a lot of work with the Duke of Edinburgh Award so he was interested in speaking about that."
Lauren Elliot added: "He was very friendly and asked what voyages I had been on.
"There are 50 young people involved in the trust in Inverclyde so feel very lucky that I got the chance to meet the royal visitors."