Snorkelling and diving的意思有什么区别?

Snorkelling and diving的意思有什么区别?
两个都是潜水,但是意思有什么区别?

Snorkel
A breathing apparatus used by skin divers,consisting of a long tube held in the mouth.
水下呼吸管：潜水员使用的由在口中置有一条长管组成的呼吸装置
A retractable vertical tube in a submarine that contains air-intake and exhaust pipes for the engines and for ventilation,permitting extended periods of submergence at periscope depth.
水下通气管：一种潜艇使用的可缩式垂直长管,装有供发机用的进排气管,使潜艇在潜望深度可延长在水底的潜水时间
dive
应该是带氧气瓶的潜水吧
你可以查查那种英汉双解得词典