If it is, I was convinced as we thumped on that reef through a tide change, the passage is not navigable. And we had company aground with us but watched a Bayfield 32 go straight through right across the reef ahead, and out into deep water headed for the USA!
All of my sailboats have been underpowered in some conditions even though they were(are) more than adequately powered in theory. It's just the nature of wind and waves.