never tried but looking at google earth seems there's access to the beach near the campsite so depends how big a boat you're trying to launch i'd say.   Otherwise it's only 17k down the coast from denham if you're in something too big to drop in off the beach?   

 You can launch a tinny from the small inlet just south of of Eagle Bluff but it can only be done on a high tide.

 You can launch a boat up to around 5m at Whalebone. perhaps that is where carnarvonite is refering to. 

Coming up to the high tide would be best. There were a few being launched when we were there.

 Will have a look myself. Have a 5 year old daughter and wife who probaly dont want to do the trip by boat from Denham. It's a 4.6 m Ali Twinfisher. Launched it from Bottle bay before

Remember  catrching good Blackies off their a few year ago.