I want to install thrusters on a 4788, how do you get access to the hull under the bunk and water tanks, I want to save a little $ and have the work area accessable. Also, the shop doing the work wants to use Lewmar , any suggestions would greatly appreciated. What do you watch for during haul out and blocking? I think these yards sometime feed the customers a little bs to make us feel better, but mishandling 30k+ lbs can break stuff. Thanks for your advice!
There are three compartments under the Mstr SR bed pedestal. The aft compartment contains the drawer stack, the fwd two have access panels under the bed mattress. The center one has a midship divider.
My thruster tube was under the floor of the mid compartment, just fwd of the drawer compartment. The thruster motor protruded thru the center of the floor about six inches. The center of the floor of this compartment was cut out for the thuster motor, the compartment fore/aft divider was modified to clear the motor, and a box was build around the motor.
A heat exchanger for the hydronic heat was installed in the port side of this compartment, and an Optima battery and charger (for the thruster) was installed on the strbd side.
Except for the Optima battery/charger mine was a Bayliner factory install, they used a Wesmar thruster.
We have a 1997 4788 with Lewmar Bow and Stern thrusters. We are exceptionally happy with the choice by the way. We have the 185TT with an 8" tunnels.
I don't think there is any easy way to install on a 4788.
You will need to pull up the carpet in your forward berth to access the aft water tank which will either need to be replaced or modified.
You will also need to remove the whole drawer assy which is about half of your bunk area. You will then have the area exposed to install the tunnel. Ours is right under the next section ahead of the drawer section. We didn't need a box built
as the height was okay but we do have an access panel installed over top of the thruster.
We have an Optima battery also installed on the starboard side.
On the aft water tank you will have the forward end that tapers up. You will either need to have that part removed or have a new one built. I had one built in Abbotsford BC for about $800 and I lost only just over 10 gallons. I had heard of some earlier installs where they claimed to have lost up to 40 gallons but that is not necessary.
I don't know where you will get your thrusters installed but in Washington I know Cap Sante Marine does a lot of Lewmar installations and they are very willing to help with any questions you may have. They didn't do our install but were still helpful.
As far as hauling out the 4788 our marina has a custom steel post with flat pads on each end that they slip through the pilothouse doors and fit right over the edge of the deck. The forward lift strap then goes right over the pads there. Works like a charm and zero stress on the bow area.