This is an interesting question and the myths of British Seapower in relation to national narratives and identity are fascinating. I can probably only answer a bit of this question, I don’t think I can cover actual solid examples of actions undertaken by individuals/institutions related to the navy that could be construed as “propaganda” (if such things existed), but I can talk a bit about how British (or more correctly English) identity might have become embroiled with the navy and sea power.

Most of this answer comes from an interesting journal article by NAM Rodger entitled “Queen Elizabeth and the Myth of Sea-Power in English History” where he discusses exactly this issue.

Simply put Rodger argues that the links between English identity and sea power was forged in the myths of French Wars of Religion and the Spanish Armada. Specifically, he stresses the importance of a) defence of Protestantism b) the concept of individual liberty (especially from Rome) c) the pursuit of private profit.

I think a direct quote might be suitable from p157

"By the end of the war (Spanish War) the essential elements of the English naval myth were securely in place. The war had been fought for England's freedom, against the mortal threat of Catholic tyranny It had been a naval triumph, and would have been more so but for the queen's hesitancy and parsimony. It had been fought at little public expense, and yielded enormous private profit. It had endowed English history with an ample stock of Protestant heroes. Above all, that part of the naval war which had seized the national imagination had been fought by private interests rather than by the crown, so that the prestige did not go to strengthen an image of royal power, but one of national liberty. It made English sea-power the ideal expression of the nation in arms. Reality, of course, did not altogether correspond with the myth, but it is too dismissive to follow a recent historian's judgement: 'the idea that the privateers were Protestant crusaders is nonsense. Like the lord admiral and his chief judge, they were primarily cheerful thieves.' In fact the idea is not complete nonsense; there was some truth in it, and in each of the elements of the new naval myth, for cheerful theft and Protestant crusading were entirely compatible "

"At the core of the English political idea of sea-power as it was now established lay a trinity of associations: religion, freedom and money"

Moving on into the 17th and 18th Century the myth of the cheap, profitable war against Catholicism was never unpopular. Rodger makes the case that when politicians stuck to these basic concepts they did not go far wrong. Importantly, he argues, the direction of naval power had to be seen for the benefit of people (business-men, privateers, entrepreneurs, etc) not the state and especially not the Crown. He suggests that the Myths of what Seapower meant for England were constantly available to a political oposition. A government may have to accept political and diplomatic realties and compromises, a “patriotic” opposition does not need to and can always bang the drum.

This appears true when you start considering events such as The War of Jenkins Ear rolling into the wider War of Austrian Succession. The profit motivations pushing England into a war with Spain, forcing open Spanish American markets, Slave contracts, and “Big Sugar” interests (I made that term up..). You can argue that private profitability is driving factor in the concepts of what a war should be. Cheap, profitable, and anti-Catholic.

The crux I think of Rodger’s article is that the concept of Sea Power helped create the myth of English/British exceptionalism embodying and differentiating themselves from that of Europe through the liberty from Catholicism and the liberty to make money. This myth became an important aspect of internal politics and early mass appeal to nationalism in the nation. Whether or not Rodger's argument really hold up..im not sure. Its a bit too sweeping for my liking and i suspect if i looked around you could probably find plenty of other views.

Interestingly Rodgers doesnt really tie these ideas into some of his wider ideas relating to "the Fiscal-Naval State" that he subscribes to. There is a body of historians who view some of the specific economic/military advances made by England/Britain during 17-19th century as intrinsically linked to seapower. They argue (very simply) that the building and maintaining the elements of seapower was hugely beneficial to every stage of a growing economy. Prompting developments in banking, insurance, construction, retail, overseas trade etc etc. Suggesting that these links were understood by those at the time and that seapower was really the engine of economic development for England/Britain.

O' Brian, Patrick K. "Inseparable Connections: Trade, Economy, Fiscal State, and the Expansion of Empire, 1688-1815." Chap. 3 In The Eighteenth Century, edited by P. J. Marshall, Alaine Low and Roger Louis, 53-77. Oxford: Oxford University Press, UK, 1998.

Rodger, N. A. M. "From the ‘Military Revolution’ to the ‘Fiscal-Naval State’." Journal for Maritime Research 13, no. 2 (2011/11/01 2011): 119-28.

———. "Queen Elizabeth and the Myth of Sea-Power in English History." Transactions of the Royal Historical Society 14 (2004): 153-74.