 If you've a boat and plenty of time to explore Ibiza's 170 km (105 miles) of coastline, so much the better.
Having a boat and plenty of time to explore the coastline doesn't make a difference.
mnli hypothesis: Having a boat and plenty of time to explore the coastline doesn't make a difference. premise:  If you've a boat and plenty of time to explore Ibiza's 170 km (105 miles) of coastline, so much the better.