Warm weather and calm seas have meant the number of #migrants tempting the crossing from northern #France to the #UK has risen sharply in recent days.Our reporters were on the beach, early in the morning, in Gravelines near Calais as a group of migrants tried, and failed, to board a small boat. They stood on the shoreline and watched as the already overcrowded boat disappeared into the distance.Migrants who spoke to FRANCE 24 said they were from…