2 valentine tanks with amphibious modification, prepareing for D day. These are 2 of 6 sunk in Poole bay that led to a change in British tactics - but not US. All British Valentines landed in Normandy successfully. All US ones failed to reach shore.
Facts about Valentine tanks sung accidently in WW2

• It is in United Kingdom
• Valentine tanks sung accidently in WW2 is in the Atlantic (European coastal).
• The typical depth is 0-20 Metres 0-60 Feet.
• The typical visibility is 3-10 Metres 10-30 Feet.