The written text reads: "Dear sister having a lovely day this is the boat but we have not the rough weather that you see here do you wish you was with us annie" Good thing their weather was better!
A stamp on the back reads: "Caledonian Steam Packet Co. Limited. P.S. Duchess of Hamilton." And some text printed on the back reads: "Caledonian Steamers via Gourock, Wemyss Bay and Ardrossan." The Caledonian Steam Packet Company formed in 1889 to complement the Caledonian Railway. More can be found about it here.
Postmarked July 1, 1909 (oops, must correct the last 3 postcard posts - they were June, not July!) 8:10pm from Gourock P.O., Renfrewshire.
Gourock is located to the top left of the map on the south side of the river, near Greenrock. Ardrossan is to the lower left with the ferry lines coming form it. As you can see, they are both relatively close to Glasgow.
Interesting notes - there is an Ardrossan here in Alberta - however, the word means "headland of the little promontory" (you can find out all about Scotland's Ardrossan here) and Alberta's Ardrossan is completely landlocked - obviously named after this or another Ardrossan somewhere else. Also, we are having a very large tree removed from our backyard today (more to come on that) and one of the fellows working on it is Scottish - quite likely from near this area - spent time in Glasgow, anyhow. Is it just me, or does everyone love a Scottish accent? Maybe it's my genes harkening back to my heritage.