Cut the cucumbers in half lengthwise, remove the seeds, and chop the pulp on a coarse grater. Squeeze out the liquid. Transfer the chopped cucumbers to a bowl.
Finely chop the peppers, add to a bowl of cucumbers, add cilantro there, 1 tablespoon. a spoon of olive oil, lime juice, garlic, and salt, mix well.
Turn on the grill to preheat to medium-high temperature. Soak 6 wooden skewers in cold water for 10 minutes.
In a separate bowl, combine shrimp with 2 tablespoon. tablespoons of olive oil and 1.5 teaspoon of salt.
String the shrimp on skewers soaked in water and grill until pink, about 2 minutes on each side.
Brush the baguette slices on both sides with olive oil and grill for about 4-5 seconds on each side.
Remove shrimps from skewers and cut them into halves.
Put 2 halves of shrimp on each crouton, and put 1 tablespoon on top. a spoonful of cucumber salad. You can serve sandwiches right away.