On the night of 18 July, Henry dined aboard Great Harry, the flagship of Admiral John Dudley, Viscount Lisle.
Toward evening, a breeze sprang up and, as Mary Rose, the flagship of Vice Admiral George Carew, advanced, she foundered and sank with the deaths of all but 35–40 of her crew.
[3] The precise reasons are not known, but it was believed at the time that the crew had forgotten to close the lower gunports after firing, so that when she heeled over in the breeze she took on water and sank.
[4] The wind subsequently died down but Lisle made use of the tides and currents to position his fleet and disrupt the formation of the larger French ships.
There were heavy casualties on both sides at the Battle of Bonchurch, the French at Sandown hastily retreated after losing their commanders in an attack on a newly built fort, and those that landed at Bembridge were ambushed.