pushing the boat out

[airbolt]

When we are prepared for spending a little extra we " push the Boat out ". What is the derivation for this?

[shaneystar]

One explanation though there are others no doubt.......
Pushing the boat out. Common enough today when it is someone's round of drinks in a pub. But the term owes its origin to Horatio Nelson. After losing his arm, the admiral installed a beautifully-made silver boat mounted on wheels which could contain two decanters of either madeira or claret. When entertaining his captains he was then able to push the wine around the table more easily. The boat is now in the Nelson Collection at Lloyd's of London.

[Quizmonster]

It's obviously naval in origin, but - oddly enough - there is no record of the phrase ever having been used before 1937.

[joko]

could it be from the tradition of splashing out on a bottle of champagne and smashing it on the side of the boat before it sets off?

[Quizmonster]

'When my boat comes in' is a variant of a legal phrase used in the Court of the Admiralty as long ago as the 1500s. The concept behind it is pivotal in the plot of Shakespeare's 'Merchant of Venice', for example.
The suggestion is that the arrival of one's "boat" signals the making of one's fortune...ie lots of money coming in. In the same way, 'to push the boat out' is to get involved in paying lots of money out. The latter is little more than an inversion of the former.
The fact that there is no recorded use of the phrase prior to the 1930s certainly suggests that it is quite a recent coinage.