The inadequacy of the regime provided by the law of the sea to effectively protect submarine cables, the relevance of which in national economies increases as time goes by, is hardly questionable. The UNCLOS, in particular, is a ‘constitutional’ convention, one that needs other instruments to be put in place in order to ensure the effectiveness of most of its provisions. As stated beforehand, BITs can provide only a partial solution to the problem – in other words, they can represent a solution only in those areas where coastal States exercise their sovereignty. In the high seas and in those areas where the sovereignty of a State is limited by the rights and duties of other States, BITs clearly cannot be a suitable solution. However, BITs and investment law in general can nonetheless represent a model worth following to fill the remaining lacunae of the law of the sea in the regime applicable to submarine cables. The lesson to be learned from investment law is that the multilateral approach is not necessarily the most appropriate. In investment law, the bilateral approach has been proven as successful as it allows each State to pursue their interest at the local level by negotiating the level of protection they deem appropriate in a particular State or region for their nationals. BITs could be a suitable instrument to reach effective and constant protection for submarine cables. Alternatively, bilateral or small multilateral treaties could help to solve once and for all the problem of the current inadequacy of the law of the sea in terms of protection of submarine cables.