Mariners beware - Southsea submarine barrier

In the same way that scuba diving isn't really a spectator sport, there's not that much to be seen at HW.

 Constructed in the early 20th century 1905-9 running from the beach out to the Horse Sand fort (seen in the distance as protection to prevent fast motor torpedo boats or small craft from getting into Portsmouth.

Constructed of 60-ton concrete blocks and heavy ironwork there is a gap that very small boats can use, although I've always preferred to sail around