Our standard mono hulls are deep vee hulls designed for an excellent ride in offshore conditions. We use a flooding keel or water ballast cavity which gives great stability at rest, and a solid feel similar to a much heavier boat. The keel is designed for rapid drainage so the boat pops onto the plane just like a conventional design. In very rough conditions a specially designed flap in the transom can be closed to keep the ballast in for a smoother ride.

Importantly when talking deep vees, our quoted vee or deadrise angle is the real or effective deadrise angle, measured to the outer corner of the chine.

Our bow shapes are different to the majority of aluminium boat designs currently on the market. Many plate aluminium kit boats have a forefoot which is both deep and sharply vee’d, which when combined with a relatively low deadrise shape aft is a recipe for broaching downwind. At best this can make steering the boat difficult, and at worst can be highly dangerous in bar crossings or very rough seas.

Our hull shapes are essentially the opposite of the above. We use a generous radius to the bow in profile and a well raked stem. This is combined with a gentle upward sweeping chine giving a hull shape which can still happily punch through chop, but will give lots of dynamic lift at the bow in following seas, rather than dig in and broach.

We run moderate sized reverse chines which keep spray down, without the pounding and harsh ride that comes with chines that are both too big, and have too much reverse angle. We also run carefully designed lower spray strakes to peel off some of the spray before it climbs further up the hull, which both increases fuel efficiency and helps keep spray down.

Click here to learn more about :

• Deadrise
• Water Ballast
• Reverse chines
• Spray Strakes
• Broaching

The post Monohulls 8.0m + appeared first on Sherwood Marine.

Our standard mono hulls are deep vee hulls designed for an excellent ride in offshore conditions. We use a flooding keel or water ballast cavity which gives great stability at rest, and a solid feel similar to a much heavier boat. The keel is designed for rapid drainage so the boat pops onto the plane just like a conventional design. In very rough conditions a specially designed flap in the transom can be closed to keep the ballast in for a smoother ride.

Importantly when talking deep vees, our quoted vee or deadrise angle is the real or effective deadrise angle, measured to the outer corner of the chine.

Our bow shapes are different to the majority of aluminium boat designs currently on the market. Many plate aluminium kit boats have a forefoot which is both deep and sharply vee’d, which when combined with a relatively low deadrise shape aft is a recipe for broaching downwind. At best this can make steering the boat difficult, and at worst can be highly dangerous in bar crossings or very rough seas.

Our hull shapes are essentially the opposite of the above. We use a generous radius to the bow in profile and a well raked stem. This is combined with a gentle upward sweeping chine giving a hull shape which can still happily punch through chop, but will give lots of dynamic lift at the bow in following seas, rather than dig in and broach.

We run moderate sized reverse chines which keep spray down, without the pounding and harsh ride that comes with chines that are both too big, and have too much reverse angle. We also run carefully designed lower spray strakes to peel off some of the spray before it climbs further up the hull, which both increases fuel efficiency and helps keep spray down.

Click here to learn more about :

• Deadrise
• Water Ballast
• Reverse chines
• Spray Strakes
• Broaching

The post Monohulls 4.5 – 6.0m appeared first on Sherwood Marine.

Our standard mono hulls are deep vee hulls designed for an excellent ride in offshore conditions. We use a flooding keel or water ballast cavity which gives great stability at rest, and a solid feel similar to a much heavier boat. The keel is designed for rapid drainage so the boat pops onto the plane just like a conventional design. In very rough conditions a specially designed flap in the transom can be closed to keep the ballast in for a smoother ride.

Importantly when talking deep vees, our quoted vee or deadrise angle is the real or effective deadrise angle, measured to the outer corner of the chine.

Our bow shapes are different to the majority of aluminium boat designs currently on the market. Many plate aluminium kit boats have a forefoot which is both deep and sharply vee’d, which when combined with a relatively low deadrise shape aft is a recipe for broaching downwind. At best this can make steering the boat difficult, and at worst can be highly dangerous in bar crossings or very rough seas.

Our hull shapes are essentially the opposite of the above. We use a generous radius to the bow in profile and a well raked stem. This is combined with a gentle upward sweeping chine giving a hull shape which can still happily punch through chop, but will give lots of dynamic lift at the bow in following seas, rather than dig in and broach.

We run moderate sized reverse chines which keep spray down, without the pounding and harsh ride that comes with chines that are both too big, and have too much reverse angle. We also run carefully designed lower spray strakes to peel off some of the spray before it climbs further up the hull, which both increases fuel efficiency and helps keep spray down.

Click here to learn more about :

• Deadrise
• Water Ballast
• Reverse chines
• Spray Strakes
• Broaching

The post Monohulls appeared first on Sherwood Marine.

Our plate alloy catamarans are based on the hull shape we created for the high tech Nauticraft R&D catamaran project. As with our mono hulls, much attention has been focused on the bow, and creating a shape that will both cut through chop, but won’t dig in to following seas. The section shapes and swept bow profile create a smooth entry, and lots of dynamic lift in hard downwind conditions. Click here to learn more about dynamic lift.

We also put a large chamfer piece between the tunnel top and hull inner sides. This further improves bow lift and helps give a smoother landing in really rough seas, or when cruising at slower speeds. We’ve found this to be much more effective in practise than putting a small central vee or “wave breaker” in the tunnel.

Our tunnel shapes are higher and have a gentle slope up to the bow, compared to other designs on the market which are much more bluff, and prone to wave impact.

Company founder David Sherwood has been designing high speed commercial catamarans for over 20 years for world leading companies.

The post Catamarans appeared first on Sherwood Marine.

Our level flotation boats are based on our range of commercial RIB style designs, using our unique double chine hullform. RIBs are generally an excellent hullform for offshore use and are chosen by many rescue organisations for this reason.

Conventional RIBs have a rigid hull bottom and deck formed from aluminium or fibreglass, and an inflatable collar which effectively forms the topsides of the boat. The narrow chine beam gives a soft ride, and the inflatable tubes give stability at rest. The volume of the tubes also gives much improved resistance to swamping.

The main drawback RIBs is the relative fragility of the inflatable collars and the expense of replacement. Our designs overcome this issue by replacing the tube with a tough polyurethane skinned, closed cell foam filled collar. We also have versions without the collar, using rigid foam filled aluminium side tanks instead. The hull shape incorporates a bevelled double chine where the inflatable tube would normally sit, which effectively replicates the overall cross section shape of the inflatable type RIBs.

Our level flotation designs meet the AS1799.1 recommendations for level flotation when swamped. These are not mandatory requirements, however building to them gives much a much improved level of safety, particularly for smaller boats used in open waters.

The result is a boat that looks and performs like a RIB, with the soft ride, stability at rest, and inherent safety, in a much more robust and durable package.

The post Level Flotation Designs & RIBS appeared first on Sherwood Marine.