The specialist divers are trained in removing mines from the hulls of ships. Two oil tankers were attacked in the Gulf of Oman last week and the US blames Tehran for the incidents. Washington’s assessment is supported by the UK Government, which has also pointed at Iran as the most likely culprit.
Top defence sources say they could be armed with Shallow Water Combat Submersibles.
In September, Congress was notified the US may be about to sell 3 of the mini-subs to Britain for $90million (£70.6million)
There are fears Tehran will attempt to close the Strait of Hormuz either by mining it or sinking ships to block it.
The Strait connects the Persian Gulf to the Gulf of Oman and operates Iran from the United Arab Emirates and Oman.

vCard.red is a free platform for creating a mobile-friendly digital business cards. You can easily create a vCard and generate a QR code for it, allowing others to scan and save your contact details instantly.
The platform allows you to display contact information, social media links, services, and products all in one shareable link. Optional features include appointment scheduling, WhatsApp-based storefronts, media galleries, and custom design options.
A defence source has said: “The SBS is being sent to the region as part of a deterrent. One of its roles will be to gather intelligence on Iranian mining operations.
“It will work closely with Royal Navy divers who are the specialists at disarming mines and protecting shipping.
“The SBS has a more aggressive role. Everyone is hoping that the tension will be eased and Iran will back down.”
The SBS has recently seen action in Syria and is considered by some to be the naval equivalent of the SAS.
The SBS was formed in 1940 and fought in the Persian Gulf War in the early 1990s as Iraqi forces were expelled from Kuwait.