Hi B4
Have you ever been to Melbourne and seen how the trams get traction between their steel wheels and the steel tracks?
Not sure if you feel like trying it /doing it but perhaps you dropping sand for a meter or so in the path of your back tyres might just get you enough traction to overcome the lack of traction on some of the ramps you use.
in the past I have seen council staff high pressure washing the growth off ramps on the Gold Coast but that probably won't help you where you are.
Good luck with it.
If it goes in can you post pics or video?
Apparently if the vehicle goes in its important to have the motor running as it happens and to not turn it off.
If you have some bystanders pull the vehicle back to wards the ramp while its still afloat you can drive it out.
Not sure if the above works here or not or only in the internet.
I guess if you drown yours in the bay and you do get it out quickly you would still be looking for a new truck.
Enough conversation..
Coffee is on
Cheers
Chimo