An inquest's heard it may never be known how an ex-serviceman from the south of the Island came by his death.
Bruce John Robert Moon's body was found on a beach south of Niarbyl last August.
Yesterday at Douglas Courthouse, Coroner of Inquests Jayne Hughes resumed a hearing into his death.
Mr Moon was identified from his tattoos and dental records.
The 57 year old, from Castletown, left the Island to travel and hadn't told friends and family he'd returned.
Pathologist Dr Irvine Long told the court he couldn't find the cause of death because signs of drowning can disappear within 48 hours.
The hearing was told Mr Moon left a folder with his sister containing £5,000 in cash as well as making funeral arrangements and donating to charities.
Coroner of Inquests Jayne Hughes says she believed Mr Moon "died of his own conscious act" but added his death "remains a mystery".
She recorded a verdict of suicide.
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