[fedesilva]

Many people cross the Atlantic every year in relatively (not like this) small boats every year. There are common procedures and knowledge available to people that do that, see here for example: http://www.yachtingmonthly.com/archive/arc-safety-checklist-...

Examples of gross negligence: being dismasted in low or moderate wind conditions because lack of maintenance to the rigging and/or motor failing because of lack of a fuel filtering system, departing when conditions are obviously not favorable (wind against current in the Gulf Stream off the US coast).

There is no such thing as a clear line but it can be established for each case I think.