Sorry for the delay, since no-one else has either seen the post, or knows anything, I have followed this one up. The embroidered version of the badge does it no justice and full stops between the lettering can also be misleading.
The badge is that of the Royal Navy Patrol Service (RNPS) and was originally a small Silver Badge… measuring roughly the size of an old shilling, it was created by Kruger Gray a well known artist and medal designer. The design had to symbolize the work of both the minesweeping and the anti-submarine personnel …took the form of a shield upon which a sinking shark, speared by a marline spike, was set against a background made up of a fishing net with two trapped enemy mines. This was flanked by two examples of the nautical knot and at the top the naval crown. Beneath the badge was a scroll bearing the letters M/S-A/S (Mine-sweeping Anti-Submarine).
Info taken from http://www.harry-tates.org.uk/history1.htm
you can find more info on the RNPS there.