There is a solid barrier all round the side of the deck to prevent man overboard scenarios. In the weather and with this much rocking, it's still very dangerous. The door/hatch for the bridge is easy enough to access, a grab rail runs around the bridge tower for safety, so you'll just have to take your time and tread carefully. Once you're through the hatch, it will be a small ladder/stairway to get to the small bridge. From what you saw on land, it's probably big enough to fit the pilot and a navigator/first mate at most.
On the port side there is a small viewing balcony the you could hit with a grapple, but odds are against a good shot in those conditions.