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The 37m (121') Dive Charter Yacht


37m Peri Laut - Dive Charter Yacht - Kasten Marine Design, Inc.
Twin Aft PerspectiveAbove Forward | Above Side | Above Aft

Copyright 2016 Michael Kasten

The Concept

The concept for this vessel is to create an aesthetically pleasing "traditional looking" luxury motor yacht for dive charters in Southeast Asia and the Indonesian Archipelago.  An additional goal was to achieve an easy flow for the divers from water, to deck, to lounge...

The design has been named "Peri Laut" which means 'Sea Nymph' or Siren' in Malay or Bhasa Indonesia.  The lineage of the design is a blend of East and West, with the superstructure having been inherited from our Indonesian Kapal Layar Mesin designs, and the hull having been derived from our motor yachts in the Vagabond series.

Hull Form

The hull is a single chine type, in order to provide economy of construction in steel, or ease of one-off construction in fiberglass.  The hull form is also designed to provide the maximum stability without resorting to deep draft. Aft is an extended stern with a double transom, in order to provide a permanent swim deck near water level, and to still achieve a safe transom design for the open ocean.  Forward, the bow is fairly upright, in order to best balance the hull shape; to provide the maximum accommodation length inside; and to offer the greatest speed under way for a given boat length.

Design Dimensions are:


Construction is intended to be either all steel for the hull and deck, with wood house structures; or alternately all can be built in fiberglass.  The overall idea is that the presentation should give the impression of being on a classic wooden yacht, but to avoid the maintenance involved with keeping a wooden yacht, and to have dry bilges...!  In order to achieve the 'look' of a classic phinisi while onboard, the house will be built in wood, or if built in GRP, the house will be clad in wood.  Inside and below the interior is to be built in wood, also conveying the classic wooden yacht experience.

36m KLM Dunia Baru - Kasten Marine Design, Inc. - Photo by Dennis Anderson  36m KLM Dunia Baru - Kasten Marine Design, Inc. - Photo by Dennis Anderson
Photos of the Dunia Baru interior - Click for Larger Images 


Since Peri Laut is relatively long and slender, the Displacement to Length is under 200.  Maximum hull speed should be in excess of 16 knots, which would require somewhere in the neighborhood of 2,200 hp.  Those last few knots however cost quite a lot... Ideally therefore power will be a more modest 1,200 hp, which should be sufficient to achieve a continuous 14 knots. The most efficient voyaging speed for this vessel is around 12 knots, for which approximately 850 hp should suffice.

To achieve a 4,000 NM range would be the ideal, and would open worldwide travel options. For this, approximately 20,000 USG of fuel would suffice. For a considerably longer endurance under power, it is a simple matter to back off a few knots. It is quite dramatic how much greater range is possible at slower speeds. At 12 knots, for example, range would be some 50% greater...


The interior is planned to accommodate 16 Dive Guests, and 16 Crew.  


There is a large swim deck aft with excellent access to the water. A pair of stairways lead up to the aft deck. The aft deck is ideal as a dive staging area. Side decks lead forward on both sides to a large fore deck, suited to locating two or more ‘seating pods’ for comfortable outside dining, with an awning cover. On the top deck there is a large "promenade deck" forward of the pilot house, with side decks leading aft to a covered "veranda deck".


Starting below forward, there is a chain locker / bosun’s locker. Aft of that is a crew cabin with berths for six crew, which also contains a crew shower / head and small laundry.  Aft of the forward crew cabin are eight dive charter guest cabins, four per side, with a central hallway for access to all. It is possible that the forward most cabins should be merged into one larger luxury suite, in which case an eighth ‘luxury suite’ is possible on the top deck.  Each of the guest cabins are ample size for a king size double berth, with en-suite head and shower compartment, writing desk, sizable wardrobe, and a couch / sofa.

Aft of the guest cabins is the engine room. The engine room has a machinery room to each side for generators, dive compressor, air conditoning, water maker, pumps, etc.. Part of one machinery room could be used as a pantry / cool room for food stores, and / or ship’s laundry, as needed. 

Aft of the engine room is another crew cabin with enough space for 10 crew plus s a crew mess (dining) area, and two crew head / shower compartments, each with a small laundry.


Starting forward, the main deck house contains a large lounge with windows all around, a dining area, a living-room area, and a bar / food service area. A staircase leads to the guest cabins below, more or less as shown in the photo above.  Aft of the lounge is the galley, with walk-in cooler / refrigerator, and large freezer. The galley has direct access to the lounge forward for service. 

Aft of the galley is a large dive shop, with direct access to the dive staging area on the aft deck.


Starting forward, the upper house contains the bridge at its forward end. Aft of the bridge there is space for the captain’s cabin to one side, and the first mate opposite. The central part of the upper house is also optionally usable for a head / shower to serve the aft luxury suite. At the aft end of the upper house is a spot for the eighth cabin – a large VIP luxury suite with its’ own veranda deck aft.  If it were preferred, the aft part of the top deck house could be dedicated as a videography and photography lab. There is in fact enough space onboard that the guest cabins can be rearranged to allow a video lab below, preserving the aft end of the upper house as a luxury guest suite.


The 121' Cive Charter Yacht Peri Laut is at present a prototype design - a concept offered as inspiration for what it might become. The goal has been to achieve a timeless classic aesthetic; a generous interior accommodation; a modest profile; an efficient hull type; and an overall presentation that would "fit-in" as a traditionally styled yacht regardless of where the vessel may be found, be it the South China Sea, Indonesia, Thailand, the Andaman Islands, or...

121' Dive Charter Yacht - PERI LAUT - Kasten Marine Design, Inc.
Click for Larger Image

Check out the following links for boats in the Vagabond series...

Vagrant 49 | Vagrant 70 | Vagabond 50 | Voyager 52 | Valdemar 53 | Valdemar 70 | 37m Peri Laut