In addition to designing new vessels and engineering marine systems, DLBA regularly analyzes existing vessels that require modifications to improve ride quality, improve performance, meet classification society requirements, or even to make a vessel safe to operate. For some questions, we've heard it before, dealt with it several times, and the solution is quick and easy. We don't always have the answer immediately on hand though, and sometimes the solution to a problem may require an in-depth analysis of the vessel, its systems, loading conditions and behaviors. Below you can find the type of questions that DLBA is regularly presented with and some of the answers that get projects started, keep projects going, and get vessels on the water and operating safely, efficiently, and quietly.

What tasks are necessary to develop a boat or yacht design?

My boat leans or heels to one side or the other when speeds are greater than 20 to 25 knots. What could cause this?

What is planing speed?

I have a twin screw/twin rudder boat. At some speeds when I steer to port, the boat will begin to turn to port, then stop turning and sometimes will begin to turn to starboard while the rudder angle remains in a position to indicate a port turn. What is happening?

My boat is sluggish; it responds with slow speed increase (poor acceleration) when I move the throttle forward. What can cause this poor response?

Annoying odors are in interior spaces of my boat as well as reaching out to neighboring vessels. Is there something that can be done to make this problem go away?

When my outboard powered boat was new it did not porpoise; now it porpoises at high speeds. What could have possibly changed?

I like my boat, but wish it would have a higher top speed. What are the implications of installing engines which are rated with substantially higher horsepower?

My boat is very wet. Spray is higher than the deck sheer at high speeds, the cockpit and wind screen are wet. The boat is especially wet with wind direction from the forward quarter and beam. Is there anything which can be done to improve this situation; that is, can the boat be changed to make it drier?

I recently installed higher horsepower engines in my boat; to keep the same shaft line the new engines had to be positioned a few inches forward of the original engine location. On sea trials we were accelerating to near full throttle when "the bow fell into a hole" and water/spray went over the fly bridge. It was scary! What happened?

Above 30+ knots my propellers begin to vibrate. Can this problem be fixed or reduced in magnitude?

My boat has a vibration at all RPM. I took it to a boatyard which had an instrument which could measure the frequency of the vibration during sea trials. The measurements indicated the vibrations were at propeller shaft rate for all boat speeds. The yard recommended that the propeller shafts be removed, straightened or replaced. Are there other causes for shaft rate vibrations?